Science of Brewing Archives - Brookston Beer Bulletin

Historic Beer Birthday: William S. Gossett

June 13, 2021 By Jay Brooks Leave a Comment

Today is the birthday of William Sealy Gosset (June 13, 1876–October 16, 1937). He “was an English statistician. He published under the pen name Student, and developed the Student’s t-distribution.” He also worked his entire career for Guinness Brewing, and was trained as a chemist, but it was his pioneering work in statstics, in which he was self-taught, that he is remembered today.

Here’s his biography, from Wikipedia:

Born in Canterbury, England to Agnes Sealy Vidal and Colonel Frederic Gosset, Gosset attended Winchester College before studying chemistry and mathematics at New College, Oxford. Upon graduating in 1899, he joined the brewery of Arthur Guinness & Son in Dublin, Ireland.

As an employee of Guinness, a progressive agro-chemical business, Gosset applied his statistical knowledge – both in the brewery and on the farm – to the selection of the best yielding varieties of barley. Gosset acquired that knowledge by study, by trial and error, and by spending two terms in 1906–1907 in the biometrical laboratory of Karl Pearson. Gosset and Pearson had a good relationship. Pearson helped Gosset with the mathematics of his papers, including the 1908 papers, but had little appreciation of their importance. The papers addressed the brewer’s concern with small samples; biometricians like Pearson, on the other hand, typically had hundreds of observations and saw no urgency in developing small-sample methods.

Another researcher at Guinness had previously published a paper containing trade secrets of the Guinness brewery. To prevent further disclosure of confidential information, Guinness prohibited its employees from publishing any papers regardless of the contained information. However, after pleading with the brewery and explaining that his mathematical and philosophical conclusions were of no possible practical use to competing brewers, he was allowed to publish them, but under a pseudonym (“Student”), to avoid difficulties with the rest of the staff. Thus his most noteworthy achievement is now called Student’s, rather than Gosset’s, t-distribution.

Gosset had almost all his papers including The probable error of a mean published in Pearson’s journal Biometrika under the pseudonym Student. It was, however, not Pearson but Ronald A. Fisher who appreciated the importance of Gosset’s small-sample work, after Gosset had written to him to say I am sending you a copy of Student’s Tables as you are the only man that’s ever likely to use them!. Fisher believed that Gosset had effected a “logical revolution”. Fisher introduced a new form of Student’s statistic, denoted t, in terms of which Gosset’s statistic was {\displaystyle z={\frac {t}{\sqrt {n-1}}}} z=\frac{t}{\sqrt{n-1}}. The t-form was adopted because it fit in with Fisher’s theory of degrees of freedom. Fisher was also responsible for applications of the t-distribution to regression analysis.

Although introduced by others, Studentized residuals are named in Student’s honour because, like the problem that led to Student’s t-distribution, the idea of adjusting for estimated standard deviations is central to that concept.

Gosset’s interest in the cultivation of barley led him to speculate that the design of experiments should aim not only at improving the average yield but also at breeding varieties whose yield was insensitive to variation in soil and climate, i.e. robust. This principle only appeared in the later thought of Ronald Fisher, and then in the work of Genichi Taguchi during the 1950s.

In 1935, Gosset left Dublin to take up the position of Head Brewer, in charge of the scientific side of production, at a new Guinness brewery at Park Royal in northwestern London. He died two years later in Beaconsfield, England, of a heart attack.

Gosset was a friend of both Pearson and Fisher, a noteworthy achievement, for each had a massive ego and a loathing for the other. He was a modest man who once cut short an admirer with the comment that “Fisher would have discovered it all anyway.”

And this biography is from the MacTutor History of Mathematics archive:

William Sealey Gosset was born on June 13, 1876 in Canterbury, England where he was the oldest of five children. He died at the age of 61 in Beaconsfield, England on October 16, 1937. He attended the Royal Military Academy in Woolwich to b ecome an engineer before he was rejected because of poor eyesight. William Gosset was never employed as a statistician. In a world of quarrelsome statistics, but he got along with everyone. He was a very helpful, quiet, patient and loyal person.

He went to school at Winchester and was well educated before entering the New College in Oxford. Here he won a first degree in chemistry in 1899. After getting his degree as a chemist, he got a job at Guinness brewery in Dublin in 1899, where he did important work on statistics, but her was never hired at a statistician. It was his environment at Guinness’ that made him a statistician. The brewery was interested in how they could make the best beer.

In 1900, the Guinness Research Laboratory was opened, which was head by the most distinguished brewing chemist, Horace Brown. Horace Brown along with the other brews were wondering how to get the raw materials for brewing beer at the cheapest but getting the best. There were many factors that they had to take into account such as varieties of barley and hops, what conditions of dying, cultivation and maturing factors.

After a few years of research, given that they were given a free hand to explore the conditions of brewing. This gave Gosset a chance to work as a statistician. He was able to take the data from the different examples of brewing to help find out which way was the best. As the young brewers work together, it seemed natural for them to take the data to Gosset to solve the numerical problems.

Gosset, in 1903, could calculate standard errors. In 1904 he wrote on the brewing of beer. This report lead to Karl Pearson consulting Gosset. Gosset met Pearson in July of 1905 when they had long talk together. Pearson, in an hour and a half, m ade Gosset understand the theory of standard errors. Gosset went back to the brewery and practiced those method for the next year. The meeting was also successful in which Pearson got Gosset to take up the study of the law of error.

Gosset wrote paper in his spare time under the name “Student.” His paper were on the probability of error of the mean and of the correlation coefficient for publication. Gosset even managed to run cooperative experiments with Hunter a nd Bennett at Ballinacurra, Buffin at Cambridge, and Beaven at Warminster in the testing of seeds against other seeds. Gosset also work with R.A. Fisher. The funny part is that Fisher did not get along Pearson, but Gosset studied under Pearson and also got along with Fisher.

To quickly recap William Gosset, he was born in 1876 and died in 1937. He did mathematical research for beer brewing, but had the problem working with only a small sample size. He work on the concept of probable errror of a mean. He also analysi sed an extended and broad range of problems such as the counting with a haemacytometer, probable error of a correlation coefficient, cereals, agronomy and the Lanarkshire milk experiment.

A very personal friend, McMullen, said this about Gosset, “he was a very kindly and tolerant and absolutely devoid malice. He rarely spoke about personal matters but when his opinion was well worth listening to and not in the least superficia l.”

Pricenomics has a good overview of Gossett’s contributions to mathematics and statistics, entitled The Guinness Brewer Who Revolutionized Statistics.

Historic Beer Birthday: Carl von Linde

June 11, 2021 By Jay Brooks Leave a Comment

Today is the birthday of Carl Paul Gottfried Linde (June 11, 1842–November 16, 1934). He “was a German scientist, engineer, and businessman. He discovered a refrigeration cycle and invented the first industrial-scale air separation and gas liquefaction processes. These breakthroughs laid the backbone for the 1913 Nobel Prize in Physics. Linde was a member of scientific and engineering associations, including being on the board of trustees of the Physikalisch-Technische Reichsanstalt and the Bavarian Academy of Sciences and Humanities. Linde was also the founder of what is now known as The Linde Group, the world’s largest industrial gases company, and ushered the creation of the supply chain of industrial gases as a profitable line of businesses. He was knighted in 1897 as Ritter von Linde.”

His importance to brewing, especially yo lager beers, is undeniable. His first refrigerating machines were built for breweries. This is situation prior to his inventions, from the University of Chicago:

Before the development of mechanical refrigeration technologies, brewers were reliant on ice harvested from lakes and ponds and stored in ice-houses. The invention of mechanical refrigeration machines provided commercial brewers with the technology necessary to keep beer for longer periods of time. Refrigeration technology was also used in special railroad boxcars, permitting brewers to ship their product over longer distances. One of the most successful early designs for a mechanical refrigeration system was invented by Carl von Linde (a professor at Munich Polytechnic School) and was an ammonia-based vapor-compression system.

One of the drawing from his first patent, in 1873.

This history of the development of Linde’s refrigeration machines is from a brochure prepared by his the company he founded, The Linde Group.

Initial contacts with breweries

After von Linde had published his ideas in 1870 and 1871 in the Polytechnic Association’s “Bavarian Industry and Trade Journal,” which he also edited, a development was set in motion that would determine the direction of the entire rest of his life. His articles on refrigeration technology had aroused the interest of brewers who had been looking for a reliable year-round method of refrigeration for the fermentation and storage of their beer. In the summer of 1871 an agreement was made between von Linde, Austrian brewer August Deiglmayr (Dreher Brewery) and Munich brewer Gabriel Sedlmayr to build a test machine according to Linde’s design at the Spaten Brewery. With their help, Linde’s ideas would be put into practice, so that a refrigeration unit could then be installed at the Dreher Brewery, the largest brewery in Austria, in the hot, humid city of Trieste (now part of Italy).

Building the first Linde ice machine

The construction plans were finally completed in January 1873 and the patent applied for. The Bavarian patent required, however, that the machine be in operation within one year. Therefore von Linde and Sedlmayr placed an order with Maschinenfabrik Augsburg that same month to build it. And with some effort they succeeded in starting operation by the important patent deadline in January 1874. Of course, the first machine did have its difficulties.

The main problem was that von Linde’s mercury seal did not work properly so that the methyl ether used as the refrigerant leaked out of the compressor. In Linde’s words, “This design was not a suitable solution for the requirements of practical use. So it seemed imperative to build a second machine.”

In order to finance it, von Linde assigned part of the patent rights to Sedlmayr, to locomotive builder Georg Krauss and to the director of Maschinenfabrik Augsburg, Heinrich von Buz. In return, they provided the funds needed for the development, building and testing of a new refrigeration machine.

Building the second refrigeration machine

With his student and assistant Friedrich Schipper, von Linde designed a new compressor, which had a significantly simpler and more effective seal. The sealing material used in the newly designed gland construction was glycerin and the more efficient ammonia was used as the refrigerant. The new machine weighed and cost only half as much as its predecessor.

In the spring of 1875 Linde ordered the new compressor from Maschinenfabrik Augsburg and submitted it for a Bavarian patent, which was awarded on March 25, 1876 for ten years. He received the German Reichspatent in August 1877.

“The very first trials with this second compressor yielded fully satisfactory results,” said von Linde, not without pride. The machine was sold to the Dreher Brewery in September 1876, erected under Schipper’s supervision and started up in spring 1877. It ran until 1908, providing refrigeration and dehumidification

Technical breakthrough

But despite this success, Linde created a third design immediately after the second machine was installed at Dreher, turning his attention to gas pumps, which were already widely used. This third, horizontal design proved to be the best cold vapor machine on the market in terms of its price/performance ratio and became the standard type of Linde compressor for decades to come. During the more than six-year development and experimentation phase, a reliable solution also had to be found for distributing the generated cold. After long trials, in executing an order for the Heineken Brewery in Rotterdam, von Linde developed a method of circulating cold saltwater brine in a pipe cooling system (natural convection cooling), which was installed on the ceiling of the refrigeration rooms.

And this inset is about the company’s “First customers and partners: brewers.”

In 1840, many continental European breweries switched to bottom fermented lager production (in contrast to the “English” top-fermented brown beers or ales) because the beer remained fresh longer and customers preferred the taste. The ice machine described by von Linde seemed ideal for achieving the required lower temperatures and to ensure precise cooling control. So it is no wonder that some major brewers showed great interest in this invention.

Gabriel Sedlmayr of the Munich Spaten Brewerey was willing to let von Linde experiment with an early refrigeration machine in his brewery in the early 1870s. The first unit functioned passably well, but was too large and had numerous flaws. The drawings submitted for the patent showed that Sedlmayr himself had a hand in the second version, which was significantly smaller in size and worked well. This unit was sold to the Trieste Dreher Brewery for air cooling.

With Sedlmayr as an intermediary, the Rotterdam Heineken Brewery under its director Feldmann ordered an ice machine in 1877 for ice production. In his collaboration with the Heineken Brewery, Linde developed “natural convection cooling” with a system of cooling pipes under the ceiling of the cellar. Feldmann in turn put von Linde in contact with J. C. Jacobsen, head of the Carlsberg Brewery in Copenhagen, who ordered a large refrigeration unit in 1878.

Karl Lang, technical adviser and supervisory board member of several Rhineland breweries, also played a significant role during the founding period of the “Gesellschaft für Linde’s Eismaschinen.” He introduced Linde to brewery director Gustav Jung, who not only ordered a refrigeration unit but also became, with Lang and banker Moritz von Hirsch, a shareholder and Supervisory Board member of the Linde Company.

The connection between the Linde Company and brewery directors was maintained to some extent over several generations. After the death of Karl Lang in 1894 his position as chairman of the Supervisory Board was taken over by Gustav Jung, followed by his son Adolf Jung in 1886. Carl Sedlmayr took over for his father Gabriel on the Supervisory Board and in 1915, the third generation of this family followed with Anton Sedlmayr. The Jung and Sedlmayr families held their Supervisory Board seats until after the Second World War.

Here’s Linde’s entry from the Oxford Companion to Beer, written by Horst Dornbush.

Linde, Carl von
was a 19th-century German engineer and one of the world’s major inventors of refrigeration technology. See refrigeration. Starting in the middle of the 18th century, many people before Linde had tinkered with artificial refrigeration contraptions, but Linde was the first to develop a practical refrigeration system that was specifically designed for keeping fermenting and maturing beer cool—in Linde’s case, Bavarian lagers—during the hot summer months. Linde was born in the village of Berndorf, in Franconia, in 1842, at a time when warm-weather brewing was strictly forbidden in his native Bavaria; no one was allowed to brew beer between Saint George’s Day (April 23) and Michael’s Day (September 29). This was to avoid warm fermentations, which provided ideal habitats for noxious airborne bacteria to proliferate and caused yeasts to produce undesirable fermentation flavors. Both made summer beers often unpalatable. Summer brewing prohibition had been in force since 1553 and was only lifted in 1850, by which time Bavarian brewers had learned to pack their fermentation cellars with ice they had laboriously harvested in the winter from frozen ponds and lakes. There had to be a better way to keep beer cold…and that was just the challenge for a budding mechanical engineering professor like Linde, who had joined Munich’s Technical University in 1868. See weihenstephan. The basic principle of refrigeration had been understood for centuries. Because cold is merely the absence of heat, to make things cold, one must withdraw heat. Compressing a medium generates heat; subsequently decompressing or evaporating it quickly absorbs heat from its environment. Devices based on this principle are now generally known as vapor-compression refrigeration systems; apply this to a fermenting or lagering vessel, and it becomes a beer-cooling system. For Linde, the next question was the choice of refrigerant. Initially he experimented with dimethyl ether but eventually settled on ammonia because of its rapid expansion (and thus cooling) properties. He called his invention an “ammonia cold machine.” Linde had received much of the funding for this development from the Spaten Brewery in Munich, which was also the first customer to install the new device—then still driven by dimethyl ether—in 1873. By 1879, Linde had quit his professorship and formed his own “Ice Machine Company,” which is still in operation today as Linde AG, headquartered in Wiesbaden, Germany. By 1890, Linde had sold 747 refrigeration units machines to various breweries and cold storage facilities. He continued to innovate and invented new devices most of his life, including equipment for liquefying air, and for the production of pure oxygen, nitrogen, and hydrogen. In 1897 he was knighted, and from then on could append the honorific “von” to his surname. He died a prosperous industrialist in Munich in 1934, at the age of 92, and today Linde AG is a leading gases and engineering company with almost 48,000 employees working in more than 100 countries worldwide. For all his many accomplishments, Linde’s pioneering work in artificial beer cooling technology is perhaps his most enduring legacy.

Historic Beer Birthday: Eduard Buchner

May 20, 2021 By Jay Brooks Leave a Comment

Today is the birthday of Eduard Buchner (May 20, 1860-August 13, 1917). Buchner was a German chemist and zymologist, and was awarded with Nobel Prize in Chemistry in 1907 for his work on fermentation.

This is a short biography from The Famous People:

Born into an educationally distinguished family, Buchner lost his father when he was barely eleven years old. His elder brother, Hans Buchner, helped him to get good education. However, financial crisis forced Eduard to give up his studies for a temporary phase and he spent this period working in preserving and canning factory. Later, he resumed his education under well-known scientists and very soon received his doctorate degree. He then began working on chemical fermentation. However, his experience at the canning factory did not really go waste. Many years later while working with his brother at the Hygiene Institute at Munich he remembered how juices were preserved by adding sugar to it and so to preserve the protein extract from the yeast cells, he added a concentrated doze of sucrose to it. What followed is history. Sugar in the presence of enzymes in the yeast broke into carbon dioxide and alcohol. Later he identified the enzyme as zymase. This chance discovery not only brought him Nobel Prize in Chemistry, but also brought about a revolution in the field of biochemistry.

Eduard Buchner is best remembered for his discovery of zymase, an enzyme mixture that promotes cell free fermentation. However, it was a chance discovery. He was then working in his brother’s laboratory in Munich trying to produce yeast cell free extracts, which the latter wanted to use in an application for immunology.

To preserve the protein in the yeast cells, Eduard Buchner added concentrated sucrose to it. Bubbles began to form soon enough. He realized that presence of enzymes in the yeast has broken down sugar into alcohol and carbon dioxide. Later, he identified this enzyme as zymase and showed that it can be extracted from yeast cells. This single discovery laid the foundation of modern biochemistry.

One of the most important aspects of his discovery proving that extracts from yeast cells could elicit fermentation is that it “contradicted a claim by Louis Pasteur that fermentation was an ‘expression of life’ and could occur only in living cells. Pasteur’s claim had put a decades-long brake on progress in fermentation research, according to an introductory speech at Buchner’s Nobel presentation. With Buchner’s results, “hitherto inaccessible territories have now been brought into the field of chemical research, and vast new prospects have been opened up to chemical science.”

In his studies, Buchner gathered liquid from crushed yeast cells. Then he demonstrated that components of the liquid, which he referred to as “zymases,” could independently produce alcohol in the presence of sugar. “Careful investigations have shown that the formation of carbon dioxide is accompanied by that of alcohol, and indeed in just the same proportions as in fermentation with live yeast,” Buchner noted in his Nobel speech.

This is a fuller biography from the Nobel Prize organization:

Eduard Buchner was born in Munich on May 20, 1860, the son of Dr. Ernst Buchner, Professor Extraordinary of Forensic Medicine and physician at the University, and Friederike née Martin.

He was originally destined for a commercial career but, after the early death of his father in 1872, his older brother Hans, ten years his senior, made it possible for him to take a more general education. He matriculated at the Grammar School in his birth-place and after a short period of study at the Munich Polytechnic in the chemical laboratory of E. Erlenmeyer senior, he started work in a preserve and canning factory, with which he later moved to Mombach on Mainz.

The problems of chemistry had greatly attracted him at the Polytechnic and in 1884 he turned afresh to new studies in pure science, mainly in chemistry with Adolf von Baeyer and in botany with Professor C. von Naegeli at the Botanic Institute, Munich.

It was at the latter, where he studied under the special supervision of his brother Hans (who later became well-known as a bacteriologist), that his first publication, Der Einfluss des Sauerstoffs auf Gärungen (The influence of oxygen on fermentations) saw the light in 1885. In the course of his research in organic chemistry he received special assistance and stimulation from T. Curtius and H. von Pechmann, who were assistants in the laboratory in those days.

The Lamont Scholarship awarded by the Philosophical Faculty for three years made it possible for him to continue his studies.

After one term in Erlangen in the laboratory of Otto Fischer, where meanwhile Curtius had been appointed director of the analytical department, he took his doctor’s degree in the University of Munich in 1888. The following year saw his appointment as Assistant Lecturer in the organic laboratory of A. von Baeyer, and in 1891 Lecturer at the University.

By means of a special monetary grant from von Baeyer, it was possible for Buchner to establish a small laboratory for the chemistry of fermentation and to give lectures and perform experiments on chemical fermentations. In 1893 the first experiments were made on the rupture of yeast cells; but because the Board of the Laboratory was of the opinion that “nothing will be achieved by this” – the grinding of the yeast cells had already been described during the past 40 years, which latter statement was confirmed by accurate study of the literature – the studies on the contents of yeast cells were set aside for three years.

In the autumn of 1893 Buchner took over the supervision of the analytical department in T. Curtius’ laboratory in the University of Kiel and established himself there, being granted the title of Professor in 1895.

In 1896 he was called as Professor Extraordinary for Analytical and Pharmaceutical Chemistry in the chemical laboratory of H. von Pechmann at the University of Tübingen.

During the autumn vacation in the same year his researches into the contents of the yeast cell were successfully recommenced in the Hygienic Institute in Munich, where his brother was on the Board of Directors. He was now able to work on a larger scale as the necessary facilities and funds were available.

On January 9, 1897, it was possible to send his first paper, Über alkoholische Gärung ohne Hefezellen (On alcoholic fermentation without yeast cells), to the editors of the Berichte der Deutschen Chemischen Gesellschaft.

In October, 1898, he was appointed to the Chair of General Chemistry in the Agricultural College in Berlin and he also held lectureships on agricultural chemistry and agricultural chemical experiments as well as on the fermentation questions of the sugar industry. In order to obtain adequate assistance for scientific research, and to be able to fully train his assistants himself, he became habilitated at the University of Berlin in 1900.

In 1909 he was transferred to the University of Breslau and from there, in 1911, to Würzburg. The results of Buchner’s discoveries on the alcoholic fermentation of sugar were set forth in the book Die Zymasegärung (Zymosis), 1903, in collaboration with his brother Professor Hans Buchner and Martin Hahn. He was awarded the Nobel Prize in 1907 for his biochemical investigations and his discovery of non-cellular fermentation.

Buchner married Lotte Stahl in 1900. When serving as a major in a field hospital at Folkschani in Roumania, he was wounded on August 3, 1917. Of these wounds received in action at the front, he died on the 13th of the same month.

Historic Beer Birthday: Emil Christian Hansen

May 8, 2021 By Jay Brooks Leave a Comment

Today is the birthday of Emil Christian Hansen (May 8, 1842-August 27, 1909). Hansen was a “Danish botanist who revolutionized beer-making through development of new ways to culture yeast. Born poor in Ribe, Denmark, he financed his education by writing novels. Though he never reached an M.Sc., in 1876, he received a gold medal for an essay on fungi, entitled “De danske Gjødningssvampe.” In 1879, he became superintendent of the Carlsberg breweries. In 1883, he successfully developed a cultivated yeast that revolutionized beer-making around the world, because Hansen by refusing to patent his method made it freely available to other brewers. He also proved there are different species of yeast. Hansen separated two species: Saccharomyces cerevisiae, an over-yeast (floating on the surface of the fermenting beer) and Saccharomyces carlsbergensis, an under-yeast (laying on the bottom of the liquid).

Here’s his entry from Encyclopedia Britannica:

Danish botanist who revolutionized the brewing industry by his discovery of a new method of cultivating pure strains of yeast.

Hansen, who began his working life as a journeyman house painter, received a Ph.D. in 1877 from the University of Copenhagen. Two years later he was appointed head of the physiology department at the Carlsberg Laboratory in Copenhagen, where he remained until his death. His research was concerned mainly with yeasts that convert carbohydrates to alcohol, and in 1888 he published an article that described his method for obtaining pure cultures of yeast. The yeast grown from these single strains was widely adopted in the bottom-fermentation brewing industries. Further investigations led him to the discovery of a number of species of yeast. He defined the characters of the different species and devised a system of classification. After further study he devised additional methods for the culture and isolation of certain species.

Emil Hansen as a young man.

This is how Carlsberg describes Hansen’s breakthrough in 1883:

The Carlsberg Laboratory made its first major scientific breakthrough when Dr. Emil Chr. Hansen developed a method for propagating pure yeast.

Fluctuations in the beer quality were not unknown at the time, but had until then been solved by thorough cleaning of all installations after suspension of production. If a brew failed, there was no use in pasteurising it; it had to be destroyed.

In 1883, the Old Carlsberg beer got infected with the beer disease and all efforts were made to find a solution to the problem.

Dr. Emil Chr. Hansen who joined the Carlsberg Laboratory in 1878 was examining the beer, and he found that it contained wild yeast. Through his studies and analyses, he discovered that only a few types of yeast (the pure yeast) are suitable for brewing, and he developed a technique to separate the pure yeast from the wild yeast cells. The problem had been solved, and the new Carlsberg yeast – Saccharomyces Carlsbergensis – was applied in the brewing process.

The propagating method revolutionised the brewing industry. Rather than to patent the process, Carlsberg published it with a detailed explanation so that anyone could build propagation equipment and use the method. Samples of the yeast – Saccharomyces Carlsbergensis – were sent to breweries around the world by request and young brewers came to Carlsberg to learn the skills.

This is the entry from Wikipedia on the history of Saccharomyces Carlsbergensis:

So-called bottom fermenting strains of brewing yeast were described as early as the 14th century in Nuremberg and have remained an indispensable part of both Franconian and Bavarian brewing culture in southern Germany through modern times. During the explosion of scientific mycological studies in the 19th century, the yeast responsible for producing these so-called “bottom fermentations” was finally given a taxonomical classification, Saccharomyces pastorianus, by the German Max Reess in 1870.

In 1883 the Dane Emil Hansen published the findings of his research at the Carlsberg brewery in Copenhagen and described the isolation of a favourable pure yeast culture that he labeled “Unterhefe Nr. I” (bottom-fermenting yeast no. 1), a culture that he identified as identical to the sample originally donated to Carlsberg in 1845 by the Spaten Brewery of Munich. This yeast soon went into industrial production in Copenhagen in 1884 as Carlberg yeast no. 1.

In 1904 Hansen published an important body of work where he reclassified the separate yeasts he worked with in terms of species, rather than as races or strains of the same species as he had previously done. Here Hansen classified a separate species of yeast isolated from the Carlsberg brewery as S. pastorianus, a name derived from and attributed to Reess 1870. This strain was admitted to the Centraalbureau voor Schimmelcultures (CBS) in 1935 as strain CBS 1538, Saccharomyces pastorianus Reess ex Hansen 1904. In a further publication in 1908, Hansen reclassified the original “Unterhefe Nr. I” as the new species Saccharomyces carlsbergensis and another yeast “Unterhefe Nr. II” as the new species Saccharomyces monacensis. The taxonomy was attributed to Hansen 1908 and the yeasts entered into the Centraalbureau voor Schimmelcultures in 1947 as CBS 1513 and CBS 1503 respectively.

Since the early 1900s, bottom-fermenting strains of brewery yeast have been typically classified as S. carlbergensis in scientific literature, and the earlier valid name assigned to a bottom-fermenting yeast by Reess in 1870 was rejected without merit. This situation was rectified using DNA-DNA reallocation techniques in 1985 when Vaughan-Martini & Kurtzman returned the species name to S. pastorianus under the type strain CBS 1538 and relegated the two former species assigned by Hansen in 1908, S. carlsbergensis CBS 1513 and S. monacensis CBS 1503, to the status of synonyms. These experiments also clearly revealed the hybrid nature of the lager brewing yeast species for the first time, even though one of the parental species was incorrectly classified in retrospect. Nonetheless, over the last decades of the 20th century, debate continued in scientific literature regarding the correct taxon, with authors using both names interchangeably to describe lager yeast.

Although most accounts mention that he wrote novels to put himself through school, one has a slightly different take, though I’m not sure how true it is. “Emil earned his bread and butter as a painter but he yearned for another life and left Ribe so he could study. He graduated from High School relatively late – he was 29 years old.”

Emil Christian Hansen, taken in 1908, a year before his death.

Historic Beer Birthday: William Cullen

April 15, 2021 By Jay Brooks Leave a Comment

Today is the birthday of William Cullen (April 15, 1710-February 5, 1790). He “was a Scottish physician, chemist and agriculturalist, and one of the most important professors at the Edinburgh Medical School, during its hay-day as the leading center of medical education in the English-speaking world.

Cullen was also a central figure in the Scottish Enlightenment. He was David Hume’s physician and friend, and on intimate terms with Adam Smith, Lord Kames (with whom he discussed theoretical and practical aspects of husbandry), Joseph Black, John Millar, and Adam Ferguson, among others.

He was President of the Royal College of Physicians and Surgeons of Glasgow (1746–47), President of the Royal College of Physicians of Edinburgh (1773–1775) and First Physician to the King in Scotland (1773–1790). He was also, incidentally, one of the prime movers in obtaining a royal charter for the Philosophical Society of Edinburgh, resulting in the formation of the Royal Society of Edinburgh in 1783.”

Cullen extended the subject of chemistry beyond medicine by connecting it to many “arts” including agriculture, bleaching, brewing, mining, and the manufacture of vinegar and alkalies. In brewing, it was the very important need for cooling using artificial refrigeration where William Cullen at the University of Glasgow in 1748 made his impact, making advances crucial to the development of refrigeration for the brewing industry when he began studying the cooling effects of liquids evaporating in a vacuum, the process by which we cool foods today. He even demonstrated artificial refrigeration for the first time in 1748.

In the Brussels Journal, in a multi-part history of beer, Cullen’s contributions are acknowledged and explained:

The principle of vacuum refrigerators is based on the fact that water in a sealed container can be made to boil if the pressure is reduced (the “boiling point” of 100 degrees Celsius refers to the situation when the external pressure equals one atmosphere; water can be made to boil at lower temperatures on a mountain top). The heat necessary for evaporation is taken from the water itself. Reducing the pressure further lowers the temperature until freezing-point is reached and ice is formed. The Scottish scholar and chemist William Cullen (1710-1790) gave one of the first documented public demonstrations of artificial refrigeration, and the United States inventor Oliver Evans (1755-1819) designed, but did not build, a refrigeration machine which ran on vapor in 1805. I. Hornsey writes in his history of beer and brewing:

“The earliest machine of this type was constructed in 1755, by Dr William Cullen, who produced the vacuum necessary purely by means of a pump. Then, in 1810, Sir John Leslie combined a vessel containing a strong sulphuric acid solution along with the air pump, the acid acting as an absorbent for water vapour in the air. This principle was taken up and elaborated upon by E.C. Carré, who in 1860 invented a machine that used ammonia as the volatile liquid instead of water….The first compression machine was manufactured by John Hague in 1834, from designs by the inventor, Jacob Perkins, who took out the original patents, and recommended that ether was used as the volatile agent. Although Hague’s machine can be regarded as the archetype for all ‘modern’ refrigerators, it never really got past the development stage, and it was left to the Australian, James Harrison, of Geelong, Victoria, to finalise the practicalities and produce a working version, which he did in 1856. By 1859, Harrison’s equipment was being manufactured commercially in New South Wales, and the first of them (which used ether as the refrigerating agent) came to Britain in 1861.”

Although the first inventor of a practical refrigerator was Oliver Evans in 1805, Cullen invented the process in 1748 which allowed the technology to be further developed. After his public demonstration of the refrigeration effects of evaporative cooling, he described the phenomenon in “Of the Cold Produced by Evaporating Fluids and of Some Other Means of Producing Cold” (Essays and Observations, Physical and Literary, vol. 2 [1756]).

Historic Beer Birthday: Joseph Priestley

March 13, 2021 By Jay Brooks Leave a Comment

Today is the birthday of English scientist Joseph Priestley (March 13, 1733-February 6, 1804). While he was also a “clergyman, natural philosopher, chemist, educator, and Liberal political theorist,” he’s perhaps best known for discovering oxygen (even though a few others lay claim to that honor). According to Wikipedia, “his early scientific interest was electricity, but he is remembered for his later work in chemistry, especially gases. He investigated the ‘fixed air’ (carbon dioxide) found in a layer above the liquid in beer brewery fermentation vats. Although known by different names at the time, he also discovered sulphur dioxide, ammonia, nitrogen oxides, carbon monoxide and silicon fluoride. Priestley is remembered for his invention of a way of making soda-water (1772), the pneumatic trough, and recognising that green plants in light released oxygen. His political opinions and support of the French Revolution, were unpopular. After his home and laboratory were set afire (1791), he sailed for America, arriving at New York on 4 Jun 1794

In the biography of Priestley at the American Chemistry Society has a sidebar about his work with fermentation:

Bubbling Beverages

In 1767, Priestley was offered a ministry in Leeds, Englane, located near a brewery. This abundant and convenient source of “fixed air” — what we now know as carbon dioxide — from fermentation sparked his lifetime investigation into the chemistry of gases. He found a way to produce artificially what occurred naturally in beer and champagne: water containing the effervescence of carbon dioxide. The method earned the Royal Society’s coveted Copley Prize and was the precursor of the modern soft-drink industry.

Even Michael Jackson, in 1994, wrote about Priestley connection to the brewing industry.

“It has been suggested that the Yorkshire square system was developed with the help of Joseph Priestley who, in 1722, delivered a paper to the Royal Society on the absorption of gases in liquids. In addition to being a scientist, and later a political dissident, he was for a time the minister of a Unitarian church in Leeds. During that period he lived next to a brewery on a site that is now Tetley’s.”

In the New World Encyclopedia, during his time in Leeds, it explains his work on carbonation.

Priestley’s house was next to a brewery, and he became fascinated with the layer of dense gas that hung over the giant vats of fermenting beer. His first experiments showed that the gas would extinguish lighted wood chips. He then noticed that the gas appeared to be heavier than normal air, as it remained in the vats and did not mix with the air in the room. The distinctive gas, which Priestley called “fixed air,” had already been discovered and named “mephitic air” by Joseph Black. It was, in fact, carbon dioxide. Priestley discovered a method of impregnating water with the carbon dioxide by placing a bowl of water above a vat of fermenting beer. The carbon dioxide soon became dissolved in the water to produce soda water, and Priestley found that the impregnated water developed a pleasant acidic taste. In 1773, he published an article on the carbonation of water (soda water), which won him the Royal Society’s Copley Medal and brought much attention to his scientific work.

He began to offer the treated water to friends as a refreshing drink. In 1772, Priestley published a paper entitled Impregnating Water with Fixed Air, in which he described a process of dripping sulfuric acid (or oil of vitriol as Priestley knew it) onto chalk to produce carbon dioxide and forcing the gas to dissolve by agitating a bowl of water in contact with the gas.

And here’s More About Priestley from the Birmingham Jewellry Quarter, whatever that is:

But his most important work was to be in the field of gases, which he called ‘airs’ (he would later chide James Keir for giving himself airs (oh dear!) by adopting the term ‘gases’ in his Dictionary of Chemistry, saying ‘I cannot help smiling at his new phraseology’). Living, as he did at the time, next to a brewery, he noticed that the gas given off from the fermenting vats drifted to the ground, implying that it was heavier than air. Moreover, he discovered that it extinguished lighted wood chips. He had discovered carbon dioxide, which he called ‘fixed air’. Devising a method of making the gas at home without brewing beer, he discovered that it produced a pleasant tangy taste when dissolved in water. By this invention of carbonated water, he had become the father of fizzy drinks!

But perhaps my favorite retelling comes from the riveting History of Industrial Gases:

The relevant findings were published in 1772, in Impregnating Water with Fixed Air

20. By this process may fixed air be given to wine, beer, and almost any liquor whatever: and when beer is become flat or dead, it will be revived by this means; but the delicate agreeable flavour, or acidulous taste communicated by the fixed air, and which is manifest in water, will hardly be perceived in wine, or other liquors which have much taste of their own.

Priestley’s apparatus for experimenting with ‘airs.’

Historic Beer Birthday: Gottlieb Sigismund Kirchhof

February 19, 2021 By Jay Brooks Leave a Comment

Today is the birthday of Gottlieb Sigismund Kirchhof (February 19, 1764-February 14, 1833). He was born in Teterow, Mecklenburg-Schwerin, but spent most of his life in St. Petersburg, Russia, and considered himself to be Russian. Trained as a pharmacist and a chemist, and “in 1812 he became the first person to convert starch into a sugar, by heating it with sulfuric acid. This sugar was eventually named glucose. He also worked out a method of refining vegetable oil, and established a factory that prepared two tons of refined oil a day. Since the sulfonic acid was not consumed, it was an early example of a catalyst.” In other research, “he provided the groundwork for scientific study of the brewing and fermentation processes.”

Here’s a biography from Encyclopedia.com.

Kirchhof’s father, Johann Christof Kirchhof, owned a pharmacy until 1783 and at the same time was a postmaster. His mother, the former Magdalena Windelbandt, was the daughter of a tin smelter.

In his youth Kirchhof helped his father run the pharmacy; after the latter’s death in 1785 he worked in various pharmacies in the duchy of Mecklenburg-Schwerin, qualifying as a journeyman apothecary. In 1792 he moved to Russia and worked in the same capacity at the St. Petersburg Chief Prescriptional Pharmacy. From 1805 he was a pharmacist and became a member of the Fizikat Medical Council, a scientific and administrative group that supervised the checking of the quality of medicaments and certain imported goods. Kirchhof began his chemical studies under Tobias Lowitz, the manager of the pharmacy, and A. A. Musin-Pushkin. A few of his works were undertaken jointly with A. N. Scherer, and all of his scientific activity was carried out in Russia. In 1805 he was elected a corresponding member, in 1809 an adjunct, and in 1812 an academician adjunct of the St. Petersburg Academy of Sciences. In 1801 Kirchhof was elected a member of the Mecklenburg Natural Science Society, in 1806 a member of the Russian Independent Economical Society, in 1812 a member of the Boston Academy of Sciences, in 1815 a member of the vienna Economical Society, and in 1816 a member of the Padua Academy of Sciences.

Kirchhof’s first major discovery was the decomposition of barite with water, which Lowitz reported in “Vermischte chemische Bemerkungen” (Chemische Annalen [1797], 179-181), explicitly mentioning the discoverer. Klaproth had discovered this reaction much earlier. In 1797 Kirchhof reported two important results: the bleaching of shellac, which had an appreciable significance for the production of sealing wax, and a wet process that made it possible to begin industrial production of cinnabar. Cinnabar was produced of such high quality that it supplanted imported cinnabar, and some was exported. In 1805 Kirchhof developed a method for refining “heavy earth” (barite) by allowing caustic potash to react with barium salts. In 1807 he entered a competition organized by the Independent Economical Society to develop a method for refining vegetable oil. In collaboration with Alexander Crichton he worked out the sulfuric acid method of refining oil and received a prize of 1,000 rubles. The two men founded an oil purifying plant in St. Petersburg on Aptekarskiy Island, the largest factory at that time, with an output of about 4,400 pounds of oil per day. In many respects (for example, in the method of adding acid and the clarification of oil by glue) Kirchhof’s method is closer to modern methods than that of Thénard (1801).

In 1809 Kirchhof resigned from the Chief Prescriptional Pharmacy but continued to carry out the assignments of the Fizikat Medical Council in his laboratory there; he also conducted investigations in his home laboratory. During this period he began prolonged research to find a method for producing gum from starch in order to supplant the imported products; he then began investigating the optimal conditions for obtaining sugar from starch.

Kirchhof studied the action of mineral and organic acids (sulfuric, hydrochloric, nitric, oxalic and so on) on starch and found that these acids inhibit the jelling of starch and promote the formation of sugar from starch. He also studied the effect of acids on the starches of potatoes, wheat, rye, and corn as well as the effect of acid concentration and temperature on the rate of hydrolysis. At the same time he was searching for new raw materials for producing sugar by the hydrolysis of starch. In 1811 Kirchhof presented to the St. Petersburg Academy of Sciences the samples of sugar and sugare syrup obtained by hydrolysis of starch in dilute acid solutions. He advanced a technological method for producing sugar that was based on his investigations published in 1812. Best results were obtained by adding 1.5 pounds of sulfuric acid in 400 parts of water to 100 pounds of starch. The duration of reaction was between twenty-four and twenty-five hours at 90-100° C. The bulk of the acid did not enter into the reaction with starch, because after completion of the reaction, Kirchhof neutralized it with a specific amount of chalk. This was the first controlled catalytic reaction.

In 1814 Kirchhof submitted to the Academy of Sciences his report “Über die Zucker bildung beim Malzen des Gestreides und beim Bebrühen seines Mehl mit kochendem Wasser,” which was published the following year in Schweigger’s Journal für Chemie und Physik. This report describes the biocatalytic (amylase) action, discovered by Kirchhof, of gluten and of malt in saccharifying starch in the presence of these agents. He showed that gluten induces saccharification of starch even at 40-60° C. in eight to ten hours. During the first hour or two the starch paste was converted into liquid, which after filtration became as transparent as water. Mashed dry barley malt saccharified the starch at 30° R. in one hour. Similarly, Kirchhof studied the starch contained in the malt, separating starch from gluten by digesting it with a 3 percent aqueous solution of caustic potash. The starch treated in this manner could not be converted into sugar. Thus he proved that malt gluten is the starting point for the formation of sugar, while starch is the source of sugar.

The catalytic enzyme hydrolysis of starch discovered by Kirchhof laid the foundation for the scientific study of brewing and distilling and resulted in the creation of the theory of the formation of alcohol.

In his last years of scientific activity Kirchhof developed a method of producing unglazed pottery by treating it with drying oils; a method to refine chervets (a substitute for cochineal) from oily substances; and a method for rendering wood, linen, paper, and other substances nonflammable. For refining chervets he suggested the regeneration of turpentine by mixing it with water and then distilling the mixture.

Kirchhof also conducted research assigned by the Academy of Sciences, including analysis of gun-powders, William Congreve’s rocket fuel, mineral samples, and mineral and organic substances.

And here’s a more thorough explanation of what he discovered, and how it applied to brewing beer, from Science Clarified:

A Brief History of Catalysis

Long before chemists recognized the existence of catalysts, ordinary people had been using the process of catalysis for a number of purposes: making soap, for instance, or fermenting wine to create vinegar, or leavening bread. Early in the nineteenth century, chemists began to take note of this phenomenon.

In 1812, Russian chemist Gottlieb Kirchhof was studying the conversion of starches to sugar in the presence of strong acids when he noticed something interesting. When a suspension of starch in water was boiled, Kirchhof observed, no change occurred in the starch. However, when he added a few drops of concentrated acid before boiling the suspension (that is, particles of starch suspended in water), he obtained a very different result. This time, the starch broke down to form glucose, a simple sugar, while the acid—which clearly had facilitated the reaction—underwent no change.

Around the same time, English chemist Sir Humphry Davy (1778-1829) noticed that in certain organic reactions, platinum acted to speed along the reaction without undergoing any change. Later on, Davy’s star pupil, the great British physicist and chemist Michael Faraday (1791-1867), demonstrated the ability of platinum to recombine hydrogen and oxygen that had been separated by the electrolysis of water. The catalytic properties of platinum later found application in catalytic converters, as we shall see.

AN IMPROVED DEFINITION

In 1835, Swedish chemist Jons Berzelius (1779-1848) provided a name to the process Kirchhof and Davy had observed from very different perspectives: catalysis, derived from the Greek words kata (“down”) and lyein (“loosen.”) As Berzelius defined it, catalysis involved an activity quite different from that of an ordinary chemical reaction. Catalysis induced decomposition in substances, resulting in the formation of new compounds—but without the catalyst itself actually entering the compound.

Berzelius’s definition assumed that a catalyst manages to do what it does without changing at all. This was perfectly adequate for describing heterogeneous catalysis, in which the catalyst and the reactants are in different phases of matter. In the platinum-catalyzed reactions that Davy and Faraday observed, for instance, the platinum is a solid, while the reaction itself takes place in a gaseous or liquid state. However, homogeneous catalysis, in which catalyst and reactants are in the same state, required a different explanation, which English chemist Alexander William Williamson (1824-1904) provided in an 1852 study.

In discussing the reaction observed by Kirchhof, of liquid sulfuric acid with starch in an aqueous solution, Williamson was able to show that the catalyst does break down in the course of the reaction. As the reaction takes place, it forms an intermediate compound, but this too is broken down before the reaction ends. The catalyst thus emerges in the same form it had at the beginning of the reaction.

Enzymes: Helpful Catalysts in the Body

In 1833, French physiologist Anselme Payen (1795-1871) isolated a material from malt that accelerated the conversion of starch to sugar, as for instance in the brewing of beer. Payen gave the name “diastase” to this substance, and in 1857, the renowned French chemist Louis Pasteur (1822-1895) suggested that lactic acid fermentation is caused by a living organism.

In fact, the catalysts studied by Pasteur are not themselves separate organisms, as German biochemist Eduard Buchner (1860-1917) showed in 1897. Buchner isolated the catalysts that bring about the fermentation of alcohol from living yeast cells—what Payen had called “diastase,” and Pasteur “ferments.” Buchner demonstrated that these are actually chemical substances, not organisms. By that time, German physiologist Willy Kahne had suggested the name “enzyme” for these catalysts in living systems.

Enzymes are made up of amino acids, which in turn are constructed from organic compounds called proteins. About 20 amino acids make up the building blocks of the many thousands of known enzymes. The beauty of an enzyme is that it speeds up complex, life-sustaining reactions in the human body—reactions that would be too slow at ordinary body temperatures. Rather than force the body to undergo harmful increases in temperature, the enzyme facilitates the reaction by opening up a different reaction pathway that allows a lower activation energy.

One example of an enzyme is cytochrome, which aids the respiratory system by catalyzing the combination of oxygen with hydrogen within the cells. Other enzymes facilitate the conversion of food to energy, and make possible a variety of other necessary biological functions.

Because numerous interactions are required in their work of catalysis, enzymes are very large, and may have atomic mass figures as high as 1 million amu. However, it should be noted that reactions are catalyzed at very specific locations—called active sites—on an enzyme. The reactant molecule fits neatly into the active site on the enzyme, much like a key fitting in a lock; hence the name of this theory, the “lock-and-model.”

Historic Beer Birthday: Morton Coutts

February 7, 2021 By Jay Brooks Leave a Comment

Today is the birthday of Morton W. Coutts (February 7, 1904-June 25, 2004) who was a “New Zealand inventor who revolutionized the science of brewing beer,” and “is best known for the continuous fermentation method.”

Here’s a basic biography from the DB Breweries website:

Morton Coutts (1904-2004) was the inheritor of a rich brewing tradition dating back to the 19th century. Like his father, W. Joseph Coutts and grandfather, Joseph Friedrich Kühtze, Morton Coutts was more an innovator and scientific brewer than a businessman. He was foundation head brewer of Dominion Breweries Ltd under (Sir) Henry Kelliher and became a director of the company after his father’s death in 1946. He and Kelliher formed a formidable team-Coutts, the boffin-like heir to a rich brewing heritage, obsessed with quality control and production innovation, and Kelliher, a confident, entrepreneurial businessman, able to hold his own with politicians and competitors.

Morton Coutts’ most important contribution was the development in the 1950s of the system of continuous fermentation, patented in 1956, to give greater beer consistency and product control. The continuous fermentation process was so named because it allows a continuous flow of ingredients in the brewing, eliminating variables to produce the ideal beer continuously. The system achieved this by scrapping open vats-the weak link in the old system-and replacing them with enclosed sealed tanks. Continuous fermentation allows the brew to flow from tank to tank, fermenting under pressure, and never coming into contact with the atmosphere, even when bottled. Coutts’ research showed that his process could produce consistent, more palatable beer with a longer shelf life than under batch brewing. A London newspaper described it as a “brewer’s dream and yours too”. Coutts patented the process, and subsequently the patent rights were sold worldwide as other brewers recognised the inherent benefits of continuous processes. Although many attempted to implement the technology, most failed due to their inability to apply the rigorous hygiene techniques developed and applied by Coutts. Eventually, in 1983, Coutts’ contribution to the industry was honoured in New Zealand.

And DB Breweries also has a timeline with key events in the brewery’s history, including dates from Coutts’ life.

The Waitemata Brewery in 1933, after it became part of DB Breweries.

As for his most influential invention, continuous fermentation, here are some resources, one from New Zealand’s Science Trust Roadshow with Morton Coutts — Continuous Fermentation System. And after I visited New Zealand, I wrote a sidebar on it for an article I did for All About Beer, and also later when a German university announced something very similar a few years ago in Everything Old Is New Again: Non-Stop Fermentation.

MortonCouttsNZBeerinnovatorchangedglobalprocesses

Coutts later in life.

Also, here’s the story of him creating DB Export The Untold Story, featuring this fun video.

Historic Beer Birthday: Louis Camille Maillard

February 4, 2021 By Jay Brooks Leave a Comment

Today is the birthday of French physician and chemist Louis Camille Maillard (February 4, 1878-May 12, 1936) who was the Doogie Howser of his era, joining the faculty of the University of Nancy when he was only sixteen. He rose to prominence thanks to his work on kidney disorders and later taught medicine at the prestigious University of Paris.

But his biggest contribution, especially to brewing, was an accidental discovery he made in 1912, which today we call the Maillard Reaction, or Browning Reaction.

Here’s the basic description, from Wikipedia:

The Maillard Reaction a chemical reaction between amino acids and reducing sugars that gives browned food its desirable flavor. Seared steaks, pan-fried dumplings, biscuits (widely known in North America as cookies), breads, toasted marshmallows, and many other foods undergo this reaction. It is named after French chemist Louis-Camille Maillard, who first described it in 1912 while attempting to reproduce biological protein synthesis.

The reaction is a form of non-enzymatic browning which typically proceeds rapidly from around 140 to 165 °C (284 to 329 °F). At higher temperatures, caramelization and subsequently pyrolysis become more pronounced.

The reactive carbonyl group of the sugar reacts with the nucleophilic amino group of the amino acid, and forms a complex mixture of poorly characterized molecules responsible for a range of odors and flavors. This process is accelerated in an alkaline environment (e.g., lye applied to darken pretzels), as the amino groups (RNH3+) are deprotonated and, hence, have an increased nucleophilicity. The type of the amino acid determines the resulting flavor. This reaction is the basis of the flavoring industry. At high temperatures, a potential carcinogen called acrylamide can be formed.

In the process, hundreds of different flavor compounds are created. These compounds, in turn, break down to form yet more new flavor compounds, and so on. Each type of food has a very distinctive set of flavor compounds that are formed during the Maillard reaction. It is these same compounds that flavor scientists have used over the years to make reaction flavors.

It was, and is, for food science and understanding how heat and cooking create flavors. If you want to dive deeper, the Warwick Medical School has an article on the Historical Development of the reaction, and NPR’s Food for Thought on the centenary of Malliard’s discovery posted 100 Years Ago, Maillard Taught Us Why Our Food Tastes Better Cooked.

But it was also very important to brewing, too, especially when it comes to malting and roasting malt to get different flavors and colors in the beer. For example, here’s UC Davis professor Charlie Bamforth writing about the Malliard Reaction in his book Grape vs. Grain.

Not surprisingly, John Mallett, in his recent book Malt: A Practical Guide from Field to Brewhouse, mentions Malliard’s contributions to brewing science.