German researchers figure out how lager first developed in Bavaria

I could be dense or missing something, but there seems to be an issue of internal consistency with the article. It states that the "brewing ordnance from 1516 (the famous Reinheitsgebot) permitted only bottom fermentation and brewing of lager-style beer" and that circumstances around the ordinance eventually led to the development of bottom fermenting yeast in the early 1600s. Other sources believe bottom fermentation in beer making was an earlier practice than this article claims.

 

@zid -- my, how Oxford has fallen.

 

Chris,

I read the article to propose that bottom fermentation of beers in 1516 (and prior) were done using Saccharomyces eubayanus yeast strains. And then later when a ‘contamination’ occurred with a Saccharomyces cerevisiae yeast strain(s) a new hybrid yeast species ‘occurred’: Saccharomyces pastorianus (which is also a bottom fermenting yeast species).

I personally ‘question’ this new theory since I am unaware of any Saccharomyces eubayanus yeast strains that are capable of producing tasty beers. Would the German brewers really ferment with Saccharomyces eubayanus yeast strains ‘way back in the day’? Maybe there is continuing research here?

An interesting ‘out of the box’ theory though.

Cheers!

 

Oh. OK. I wish the article was clearer.

 

What did you expect from Oxford scholars?

 

If Saccharomyces eubayanus wasn't the best possible they were lucky it mated with Saccharomyces cerevisiae to form Saccharomyces pastorianus. Good beer in the cold. We just needed Bohemia anno 1842, and got the a bit over the top lager reign.

 

Yes, if Saccharomyces eubayanus was indeed the type of yeast used to ferment German beers way 'back in the day' it is fortuitous that the hybrid yeast (Saccharomyces pastorianus) developed.

Still, color me skeptical about this new theory.

Cheers!

 

Wiki:

https://en.m.wikipedia.org/wiki/Saccharomyces_eubayanus. My counting gives the Viking era. We also need to remember the cold conditioned Kölsch, so top fermented regular Saccharomyces cerevisiae can be used. Question is, if the annals from back then tell reliably if there was in fact bottom fermented vs top fermented.

 

I don't know, I'd say given these two charts from the era, I'd say it happened earlier than that.

I am surprised at the list of the largest breweries that Bass and Guinness are not on it, so it's possible it was originally a list of the world's largest lager brewers? (Too lazy to look up the barrelage of those two brewers at the time). But given what were the predominant type of beer produced in the countries listed, I gotta think lager was outselling ale earlier than the 20th century.

 

It appears that you are interested in this topic.

OK, let’s establish some baseline facts for continued discussion.

Saccharomyces pastorianus

Saccharomyces pastorianus is a hybrid with parentage from two yeast specifies: Saccharomyces cerevisiae and Saccharomyces eubayanus.

When did Saccharomyces pastorianus develop?

There is no way to know exactly when this hybridization occurred buy in brewing history literature the 1400’s is commonly discussed:

“Lager yeast (Saccharomyces pastorianus)

Compared to the ancient species of Saccharomyces cerevisiae, Saccharomyces pastorianus is a relatively modern species.

Nobody really knows when lager yeast first ‘happened’ but it is commonly described as being sometime in the 1400’s with lager beers being produced in Central Europe (e.g., present day Germany/Czech Republic).

Genetic studies reveal that lager yeast (Saccharomyces pastorianus) is a hybrid of Saccharomyces cerevisiae (ale yeast) and Saccharomyces eubayanus.

A number of years ago they discovered Saccharomyces eubayanus in the forests of Patagonia (South America). So some folks opined that this was the source for creating the hybrid Saccharomyces pastorianus. But how the heck did this yeast get from Patagonia to Central Europe over 500 years ago. Christopher Columbus did not arrive to the New World until 1492. I am not aware that there was any trading between South America and Europe before then.

Now, Saccharomyces eubayanus exists in other parts of the world (e.g., China) and there has been regular commerce between Europe and China since the times of Marco Polo (13th century). Maybe some yeast ‘hitchhiked’ on some trading goods?

Below is from an Abstract from a technical paper published in 2019:

“Our genome analysis together with previous reports in the sister species S. uvarum strongly suggests that the S. eubayanus ancestor could have originated in Patagonia or the Southern Hemisphere, rather than China, yet further studies are needed to resolve this conflicting scenario. Understanding S. eubayanus evolutionary history is crucial to resolve the unknown origin of the lager yeast and might open new avenues for biotechnological applications.”

https://www.biorxiv.org/content/10.1101/709253v1

Perhaps with further genetic studies we will learn more here.”

The above quoted material is from:

https://www.morebeer.com/articles/Fermenting_beer

What does “bottom fermented” really mean here?

Rather than using a ‘metric’ of where fermentation is occulting, I am of the opinion that discussing temperature is more relevant here. When it came to fermenting beer in Germany circa 1500 what was needed was yeast that are cold tolerant. The type of yeast most used for fermenting beer is the species Saccharomyces cerevisiae but this species is less than ideal for cold fermentation conditions. You made mention of Kölsch which is fermented with a strain of Saccharomyces cerevisiae which is capable of fermenting under cool(er) conditions; I ferment my Kölsch beers at 60 °F (15.6 °C) and after primary fermentation is complete I then lager (cold condition) the finished beer. I would never ferment my Kölsch at the same temperatures I ferment my lagers (e.g., low-50’s °F) since this is too cold for a Saccharomyces cerevisiae (Kölsch) yeast stain.

Is Saccharomyces eubayanus a type of yeast that is used to ferment beer?

There is a short answer to this question: no.

But the theory proposed in this article is that the German brewers of circa 1500 were using Saccharomyces eubayanus as their yeast (since it was cold tolerant). This viewpoint is contrary to past theories which makes it an interesting/novel theory. Will we ever really know the answer to this ‘question’? It seem to me that we would need to collect archeological evidence of the presence of Saccharomyces eubayanus from a German brewery circa 1500. This sort of research has no been done (yet?) but maybe we will know more in the future.

Follow the science!

Cheers!

 

I wouldn't be sure about the year of 1900. Yes, the world was taken by storm after Pilsen 1842, but things take time. For example the ale culture in Britain and empire was strong. I would also guess if you look at all the world with limited refrigeration capacities, ale could still have been even the main choice.

 

We know how to copy-paste Saccharomyces

 

The context you need for this is that by 1890 Germany, having industrialised later than Britain, was catching up and overtaking it economically. It was starting to challenge – successfully, as Jess’s table shows – British beer exports with its own lager beer, which had the advantage for export markets of being more stable.

By the early 20th century the world outside the British empire was mostly drinking lager. British brewers relied more and more on empire markets. When the colonial nations won freedom from the empire after WWII, it was a hard blow to a number of British breweries who had grown dependent on those markets.

 

I don't know the answer to this. But the researchers do point out that there was no such thing as a pure yeast culture at the time. Every pitching yeast was a mixture of different strains of yeast and probably bacteria as well. Part of the skill of the brewer was to run the fermentation in a way that encouraged the cold-tolerant yeast strains to predominate.

Not having ever drunk a beer fermented with S. bayanus myself, I am not familiar with the deficiencies of the beer it produces. But perhaps the other strains in the pitching yeast contributed flavors that made the beer more palatable than S. bayanus alone?

 

There was a presentation provided at a past National Homebrewers Conference (HomebrewCon) where they discussed homebrewed beers produced using a Saccharomyces eubayanus yeast strain. Two aspects discussed were poor attenuation and phenolics. A less than ideal sort of yeast for a lager from my perspective.

I suppose this is possible but if the beers were fermented at cold temperatures this would rule out Saccharomyces cerevisiae strains as being contributors.

Cheers!

 

Attenuation wouldn't be an issue for medieval Bavarians who regarded beer as food. Bavarian lagers displayed low attenuation right up until recent times.

I don't really want to continue about the flavour contribution of non-bayanus yeast, because it's mere wild speculation on my part – however, we'd also be looking at temperatures of ~5º C in the old caves, the natural temperature, rather than the –1ºC of lager conditioning today. That’s warm enough for S. cerevisiae to be active to some degree, I think.

 

I am not aware of any Saccharomyces cerevisiae strains that will properly ferment at 5 °C (41 °F). If you know of any that do, please let me know.

As regards Saccharomyces cerevisiae yeast strains and fermentation temperatures I am brewing right now my annual batch of Bitter Ale and I will be fermenting with the Timothy Taylor yeast strain at 70 °F (about 21 °C).

Cheers!

P.S And as regards fermenting a lager with a Saccharomyces eubayanus yeast strain I would think the presence of off-flavors (i.e., phenolics) would be most troublesome (for me).

 

We have no real way of knowing whether medieval drinkers would be as troubled by phenolic off-flavours as you or I, though. Presumably they'd be used to it.

 

Or maybe those lagers did not have phenolics since they were fermented with Saccharomyces pastorianus yeast strains.

Cheers!