Yeast – Page 4 – A Good Beer Blog

So – When Was Lager Invented… Discovered… Evolved?

This is either just a bit weird or I have completely missed something. Apparently some scientists have been looking to find the yeast strain that started lager… and they think they have found it:

When the team brought the yeast to a lab at the University of Colorado and analyzed its genome, they discovered that it was 99.5% identical to the non-ale portion of the S. pastorianus genome, suggesting it was indeed lager yeast’s long-lost ancestor. “The DNA evidence is strong,” said Gavin Sherlock, a geneticist at Stanford University who has studied lager yeast but was not involved in this study. But Sherlock wondered how S. eubayanus could have traveled the nearly 8,000 miles from Argentina to Germany. “We all know that in 1492, Columbus sailed the ocean blue,” he said. “Lager was invented in the 1400s. It’s not really clear how that progenitor would have gotten from South America to Europe.”

Whazzates’sayin’?!?! Look, don’t get me wrong – yeast is interesting stuff. But to say lager was “invented” in the 1400? Now, if I dip into my copy of Hornsey, I don’t run into lager until the 1800s at page 485. Yet this story I posted in 2008 speaks of lager yeast evolving in the 16th century in a Bavarian cave which gets us in the ball park in terms of centuries. Maybe it’s the use of the word “invented” in the article that threw me off.

Most interesting of all, Gavin Sherlock posted a comment at this here blog back in 2008 as did Drs Dunn and Sussman all involved in this project. I will stay well away from the term “egg head” this time and invite some direction on their work and the implications for the lagered time line.

Yuck! That Yeast Is Flocculating Itself Again!!!

When I was a home brewer – as opposed to a person who has home brewing supplies and equipment in the house but never does anything with it all – I used to be concerned about flocculation. Flocculation is the word that describes the capacity of a yeast (or other stuff for all I know) to clump. It is a fancy pants word for clumpiness – but is more about the propensity to clump as opposed to the clump itself. I think. If a yeast strain floucculated too much it could cause precipitation leading to poor attenuation due to separation of yeast and wort. Yet if the yeast was under flocculating there would be difficulty in settling out and creating a bright beer. I think.

So, it is comforting to know that all my half baked understanding of yeast clump-a-bility is actually related to a massively important scientific moment:

A team of scientists at Harvard University reported last week that they isolated the single gene that allows yeast to stick together. That gene allows the normally solitary yeast cells to shield themselves from toxins in their environment by banding together in protective balls. Since one of those toxins is the ethanol that the yeast themselves produce, grouping together allows the yeast to survive in the alcohol-rich environment that results from brewing. What’s more, the gene has a built in social value system that prevents yeast cells without the gene from taking advantage of the yeast flock’s protective sphere. That social control mechanism is an example of how single cells can regulate function in larger units.

Excellent! I knew that something about beer was out there promoting social values…or is it promoting socialism!?!?¹

The point? As Kevin Verstrepen, one of the eggheads in white lab coats² – a Haavaad man no less – notes: “You can look at it as a model of how single-cellular organisms can cooperate, taking a small step toward multicellular life.” A-ha! No, not the Norwegian 80’s band…I mean “a-ha” as in light-klicky-on, as in “EUREKA!!!” So not only was the creation of civilization dependent on beer but the core zymurgystic fact of beer is also the same core fact of complex life as we know it. See? Without the making of alcohol, we are all single cell amoeba… amoebae… amoebas. I think. Which leads me to my amoeba joke: “two amoeba leave a bar and look up at a bright light. One says to the other ‘is that the sun or the moon?’ to which the other replies ‘I dunno. I don’t live around here.'” Get it? That is what we would have to put up with were it not for the flocculating powers of yeast. And nobody wants that.

^¹Cue the theremin music!
^²…and let’s not have a repeat of the whole “sensitive yeast scientist” thing this time, ok?

More Yeasty History, More Yeasty Science

It seems like just a couple of weeks ago that I was learning about yeast history through science. Oh. It was just a couple of weeks ago. Now, instead of reaching back just four centuries, science is taking us back through over 400,000 centuries of yeastiness:

Why is it, even though there are 38,000 results for the Google search “Raul Cano beer“, that I have never heard of this? Look – it even has a website. You never tell me anything. More about the back story here but the interesting thing is not that it is done so much as it is not done more. Think about this. If dormant yeast can sit in the belly of a bug enclosed in amber, it must be lots of other places. I recall seeing some history show about medieval life in which the historian in charge of some European farming community site explained how, when they wondered about how they could figure out what food grains had grown there, they realized it was all around them in the deepest layers of the thatched roofs.

Hornsey describes how pot shards from pre-historic digs are studied for chemical residues to confirm their use in brewing. So, what is like a thatched roof and like amber that could hide a yeast that just happened to be used in the porter breweries of 1700s London or a dark ages monastery? Where can dormant yeast hide? Can it be sitting in a deeply buried layer of turf hibernating next to the old brewery wall or in a dried up goo residue that long ago seeped its way into the cracks in the beams of a 1400s ale house? Can it be identified that closely? And what do you call that search – is it yeast forensics? Or is it more like microbial archaeology? Is someone out there doing this right now? Are you holding back about that, too?

Two Lager Yeast Strains, Two Homecaves

I am sure I will get this wrong and that Ron will be able to clarify but it appears that two forensic yeast researchers have determined that lager yeast came into existence twice during two separate events:

…the team discovered that it happened at least twice in two separate locations in Europe, giving rise to the two different lager families…The hybrid, which makes lager instead of ale, probably evolved in Bavarian beer-brewing cellars during the 16th century. The team also found that Saaz yeasts have a single copy of each parent yeast’s genome, whereas the Frohberg yeasts have an extra copy from S. cerevisiae. They believe this difference affects the flavour of the lager, as well as how quickly the yeasts can ferment the hops.

OK, so the egg heads in lab coats don’t know that hops do not do the fermenting. Forgive them. Take a breath. There, that’s better. Apparently, that there are Saaz and Frohberg strains of lager yeast has been long known. But what was not known was that they developed independently from each other – as this article in today’s New Scientist explains in further detail. Sadly, they cannot trace back to which Bavarian cave gave birth to which strain and when. Even more detail here including this interesting tidbit:

Studying the spread of the two groups provides a genetic snapshot of lager brewing in Europe during the past 600 years: one lineage is associated primarily with Carlsberg breweries in Denmark and others in what is now Czechoslovakia, while the other group localizes to breweries in the Netherlands, including Heineken.

Neato. The team’s full research results will be published tomorrow by Genome Research.

Maine: Export Ale, Shipyard, Portland

I got a little fancy the photo effects but this is one of my first favorite south of the border ales and the only US beer I ever saw listed anywhere as a “Canadian ale” but I am thinking this is very like Mendocino Eye of Hawk and Special London Ale from Youngs.

A rocky off-white head sits over orange-amber ale. Soft water and a lovely aroma of marmalade. Rich malty and a tad sweet, this is a very clean brew with a nice edge of twiggy hops cutting through. I swear I taste a salty tang which is not too odd given where Shipyard brews its beer. If you don’t like the ringwood yeast, you will find an odd note. I like the ringwood yeast.