The Difference Between A Lager And An Ale

BeerSci
Here’s another interesting post on brewing science from Popular Science‘s BeerSci series. If you’re reading the Bulletin, chances are you’re already pretty familiar with the question What Is The Difference Between A Lager And An Ale? But author Martha Harbison gives a good overview of the technical differences in layman’s terms and goes into yeast’s history. It’s a great tale, which she refers to hilariously as a “unicellular soap opera.”

lager-yeast
“From Eubayanus to Pastorianus Ale yeast and yeast from the forests of Patagonia met in a brewery…and lager was born! Libkind et al., PNAS; August 2011″
Click here to see the chart full size.

Selecting And Generating Superior Yeasts For The Brewing Industry

yeast-cell
After my post a couple of days ago about Genetically Engineered Yeast, Chaz from Alaskan Brewing sent me a link to an interesting blog post by Dmitri, an amateur yeast wrangler who writes about his yeasty adventures at BKYeast. The post is a review of science literature from Cerevisia, the Belgian Journal of Brewing and Biotechnology. The article in question is titled Selecting and Generating Superior Yeasts for the Brewing Industry, which was published in 2012. It’s deliciously geeky and technical, but should be scrutable to anyone who brews either professionally or at home, thanks to Dmitri’s writing, as his goal is to take the jargon and science and make it accessible to a broader audience. As brewers struggle to have their beers stand out in an ever-increasingly crowded marketplace, it should be obvious that we’ll be seeing more and more experimentation with flavors and ingredients and ultimately more unique beers, and even new types of beers as others copy the successful ones, in the coming years. As the author notes, new varieties of hops are already facilitating that effort, and it seems likely that new strains of yeast are a logical next step in that evolution. And that’s what this research by a group from Leuven, Belgium is trying to make easier, finding the right yeast to create the right range of flavors for your beer. Give it a read.

yeast-map
“Graphical representation (heat map) of different characteristics of industrial yeast strains. Every row consists of data from a different yeast strain, every column is a different characteristic. ‘Yellow’ is a low score, and ‘red’ is a high score for this certain characteristic. The dendrogram on the left represents the genetic relatedness of the yeasts, based on an AFLP fingerprint exploiting transposon TY1 insertion site polymorphisms. The colour code on the top right indicates the origin of the yeast strains. This kind of analysis allows us to select yeasts with specific beneficial traits, for example to use in industry, or for breeding.”

Genetically Engineered Yeast

yeast-buddy
Mashable had an interesting piece about Genetically Engineered Yeast being done by at least two companines, Amyris and Evolva, and based in part on a New York Times article, What’s That Smell? Exotic Scents Made From Re-engineered Yeast. In the Times article Amyris co-founder Jay Keasling explained “that the process is ‘just like brewing beer, but rather than spit out alcohol, the yeast spits out these products.'” The relatively new discipline, dubbed synthetic biology, is only about a decade old. There are apparently issues about whether it would be considered natural. SOme say no, because the synthetic version “contains scores of components besides” what it’s being used as, while John B. Hallagan, from the Flavor and Extract Manufacturers Association believes “it conceivably could be called a natural ingredient since it is made in a living organism.”

Synthetic Yeast

yeast-cell
According to the UK Telegraph, a worldwide effort is underway to create Synthetic Yeast, which scientists believe will allow brewers to “make beer cheaper and stronger.”

From the article:

Researchers, who have been awarded £1 million of government funding for the project, will first attempt to recreate a slimmed down version of Saccharomyces cerevisiae, the yeast used in the brewing industry to ferment beer.

It will be the first time a genome has been built from scratch for a eukaryotic organism, the branch of the evolutionary tree that includes plants and animals.

The scientists then aim to redesign parts of the yeast genome so that it can perform functions that are not possible naturally.

Professor Paul Freemont, from the centre for synthetic biology and innovation at Imperial College London who is helping to lead the British part of the project, said they could help make yeast more efficient so they required less energy and could tolerate more alcohol before dying, allowing beer to be made stronger.

He said: “The brewing industry is very interested in this project for any new opportunities it may present as they use yeast to manufacture beer.

“One of the aims of the project is to develop this yeast strain as a vehicle that you can put in new chemical pathways and directly manipulate it in a way that is not possible at the moment.

“Clearly there are strains of yeast that are highly resistant to alcohol, but they all die off as the alcohol gets higher, so making more alcohol resistant strains will be very useful for that industry in terms of cost value.

“Strains that are metabolically more optimal and don’t require as much energy will also be useful.”

The synthetic yeast project, also known as Sc2.0, will draw together expertise from around the world.

I can’t quite decide yet whether I think this is a good idea, offering brewers many more choices and opportunities to create unique beers or a Frankenstein moment of science going too far in manipulating an essentially natural process. I guess time will tell.

beer-yeast

Yeast Evolution Due To Reuse

yeast-buddy
Today’s infographic is almost a humorous one, although it does illustrate a brewing principal, that of how genrations of yeast can be propagated for homebrewing. It was created by the Half Moon Brewer. Whatever you do, avoid the zombie yeast. I actually have one of those yeast stuffed animals in my office. I probably won’t be able to look at it the same way again.

YeastEvoChart
Click here to see the chart full size.