Today in 1962, US Patent 3044879 A was issued, an invention of William C. Herwig, Thomas L. Kissel, and Gilbert H. Koch, assigned to Miller Brewing, for his “Anactinic Malt Product and Hop Extract Therefor.” There’s no Abstract, although in the description it includes these claims:
This invention relates to manufacture of anactinic malt beverages such as beer and ale, and to intermediate products.
It is well known that beer and ale and similar malt beverages are produced from water, barley malt, adjuncts and hops. The malt and adjuncts furnish the carbohydrates and other growth essentials which make up the wort. This wort, boiled with hops, in turn forms the basic substance for fermentation in the fermenting tanks. The hops give the characteristic bitter flavor and pleasant aroma to the beer. They assist in preserving the beer and improve its foam holding capacity.
Unfortunately, beer and ale and other similar malt beverages are not stable to light. Light of both visible and-invisible wave lengths affects them adversely producing actinic damage in the form of a characteristic skunky odor. Such a beer is commonly known as light struck. The actinism is caused by chemical changes, producing compounds probably mercaptans in nature. Tests show that the olfactory threshold level of odoriferous compounds of this character is very low, in the range of a few parts per billion. This shows clearly the acute nature of the problem. 7 Many efforts have been made in the past to overcome this difficulty. Much time has been expended on packaging of beer and ale to exclude light. Colored bottles have been used and opaque packages are common. It is not uncommon to label them Do Not Expose to Light.
To compete with modern day merchandising, a malt beverage has to be removed from the case and put on the shelf, or at least a portion of the container is exposed for easy vision and access. Modern reach-in coolers have clear glass windows and fluorescent lights which aggravate the problems. Even canned beer or keg beer can be adversely affected by sunlight if, as is usually the’ case, it is drunk from a glass. glass to direct sunlight for a short a time as a few minutes will result in the impairment of the taste and production of the characteristic skunky odor. Beer at picnics and sporting events is often exposed for hours to direct sunlight. In such cases, the deleterious effects can be very marked.
q We have discovered a way to overcome the hazard of product exposure to light which forms the basis of our invention, and have thereby achieved a substantially anactinic malt beverage. The term anactinic is intended The exposure of beer in the 3,044,879 Patented July 17, 1962 bitterness in the finished product, but eliminate the photoactive elements thereof.
A still further object of the, present invention is to provide a method of treating hop extract in the presence of a reducing agent to provide a concentrated product having particular application in malt beverages production, whereby its use will not affect the desired characteristics of the beverage, but will eliminate photoactive elements therein.
The soft resins and oils, which are contained in the glands produced on the hops and known as lupulin glands, are valuable constituents of the hops as used ,in the brewing process. The soft resins consist principally of (a) the alpha acids, (b) the beta acids, and (c) the uncharacterized soft resins. The alpha acids are known as humulones and the beta acids are known as lupulones. The alpha acids are the source of antiseptic and bitter substances in beer. The beta acids or lupulones have low solubility in kettle wort and beer, thus do not appreciably enter into the brewing process.
It is known that chemical changes are made in the humulones during brewing resulting in the compounds known :as isohumulones, i.e. isohumulone, isocohumwlone, isoadhurnulone, and isoprehumulone. These isocompounds are formed in the kettle during the boiling stage of the brewing process, and we have discovered that these compounds are the ones that cause the beer to become sensitive to light in the presence of sulfhydryl comhumulone, and prehumulone, is isomerized to the corresponding isohumulones. It is known that during the isomerization of the humulones to isohumulones, a new side chain is formed which now contains a carbonyl group.
It is these isohumulones-isohumulone, isocohumuloue isoadhumulone, and isoprehumulone which we have found to be involved in the photochemical reaction with sulfhydryl compounds to produce the ‘actinic damage resulting in the characteristic light struck aroma.
to succinctly describe a beverage which will not be subject to actinic damage. The word is herein coined and is derived from the word -actinic plus the prefix an, meaning not. This is the Greek equivalent to the Latin in and consists of alpha privative plus nu movable.
We have found that three factors are necessary for the reaction causing malt beverages. to become light struck. They are photo energy in the wave length region of 1,000 to 10,000 angstroms, a sulfhydryl bearing compound, and a chemical component derived from the raw materials, hops, during the brewing process.
The primary object of the invention is to provide a hop extract and malt beverage that is stable to light and will not produce unpleasant olfactory characteristics.
A further object of the invention is to so treat the hops in malt beverages so as to retain the aroma, bouquet and We are of the belief that when the isohumulones are group can be altered by means of reduction to a secondary alcohol, and by such alternation, be prevented from reacting with the sulfhydryl groups normally present in beer components.
