Ale, beer and ... hops.

[Northern_Brewer]

...and for part of the study they weren't. The electron microscopothy of the slurry, from which they appear to derive the composition percentages, identified cell structures which doesn't necessarily imply viability.

Where do you get that from? Because the tables are derived from DNA "The range of fungi and bacteria with a greater than 1% proportion of reads from DNA isolated from bottle W1 is listed in Table 2. "

And even if they were doing things based on microscopy, the same argument applies about degradation, even if some of the more arcane arguments about selective amplification of DNA would not apply.

 

[Sadfield]

"The range of fungi and bacteria with a greater than 1% proportion of reads from DNA isolated from bottle W1 is listed in Table 2. "

Surely, that on its own would require dna extraction from every single cell? and given that some of the dna analysis was done from cultures, then some form of cell counting and correlation would have been required.

Either way there's a relative confidence in the conclusion and in the subsequent recreation of the recovered beer that debaryomyces was the dominant strain.

 

[peebee]

Happy New Year!

Hopefully we'll hear no more of that completely off-subject "yeast" business. This is a thread on Ale and hops in the 17th Century, not two well respected forumites failing to agree about the microbiological contents of three bottles of beer brewed 250 years after the times in question. Although I did originally encourage it (sorry).

I'll reiterate:

So, I want help! Can anyone point me at good information supporting the existence (or not) of hopped ales during the English Civil War (1642–1651)?

But this off-subject digression has hardened my attitude on the subject of yeast; for which I'm thankful! For this project there's just no point pursuing that subject! We get hints that ales were sweet and therefore low attenuated: A low-attenuating yeast (saccharomyces or whatever) of little flavour character in its own would seem to fit the bill. There doesn't seem much point wasting time with liquid yeast (WY-1099 was a favourite of mine), packets of dry S-33 or Windsor yeast should do the job. If the yeast has character, what can be the evidence for including that character?

I'm a strong believer in pursuing these "projects" to achieve something I like to drink. We're home-brewers, not experimental archaeologists, so add what you like (as long as there's no evidence to contradict it) but don't try to make people believe its the correct way of doing it.


Now to get back to that lengthy dissertation @Hazelwood Brewery left me with ...

 

[Sadfield]

I'm a strong believer in pursuing these "projects" to achieve something I like to drink. We're home-brewers, not experimental archaeologists, so add what you like (as long as there's no evidence to contradict it) but don't try to make people believe its the correct way of doing it.

Well the deviation is evidence that beer or ale was fermented with a mixed culture, then and before and not a single isolated strain of s-33 from c500 years after the fact.

 

[Northern_Brewer]

Surely, that on its own would require dna extraction from every single cell? and given that some of the dna analysis was done from cultures, then some form of cell counting and correlation would have been required.

The DNA analysis of cultures is a separate thing, just to confirm their identity. But the population stuff in Table 2 etc is based on DNA that "was extracted from sediments" from centrifuging a "1 mL beer sample", whether it is in a cell or not - in most cases it won't be "an extraction from a single cell", it will have been released after death. It's a bit like doing DNA fingerprinting of a crime scene.

Either way there's a relative confidence in the conclusion and in the subsequent recreation of the recovered beer that debaryomyces was the dominant strain.

As a microbiologist I see nothing in the data to suggest that Debaryomyces was "the dominant strain" in the original beers, and the conclusion of the paper certainly does not say that. The nearest it gets is "It is possible then that the presence of Debaryomyces species in both the Wallachia and King's ale samples suggests it was a more prevalent species in historic brewing and worthy of consideration for future brewing studies. "

But that doesn't mean it's responsible in any way for the primary fermentation. I would regard Harveys Le Coq Imperial Stout as the template here - AIUI you can't even detect Debaryomyces in the original wort, but Miles Jenner thinks it's airborne in the brewery and it grows slowly to become part of the "zoo" of microrganisms that contribute to the flavours acquired during the 12 months maturation in closed steel tanks. Think of Debaryomyces as another kind of Brett in effect.

 

[Northern_Brewer]

We get hints that ales were sweet and therefore low attenuated: A low-attenuating yeast (saccharomyces or whatever) of little flavour character in its own would seem to fit the bill. There doesn't seem much point wasting time with liquid yeast (WY-1099 was a favourite of mine), packets of dry S-33 or Windsor yeast should do the job. If the yeast has character, what can be the evidence for including that character?

Well I think it depends on what you call "character" - you seem to be using it as a proxy for "non-phenolic", or at least "non-wild" character. And given that (regardless of what US homebrew labs try to tell you), phenolic Saccharomyces are pretty common in British brewing even today, I don't think you can assume that there were no phenolics from the primary fermentation, "clean" non-phenolic fermentation is one of the major achievements of yeast domestication. You'd have to look at the detailed genomics of both the phenolic genes and the sugar-munching genes to get an idea of the evolutionary history.

Although the low attenuation will have come from primitive malting technology rather than lack of attenuation from the yeast, it's a reasonable way to reproduce it. I still might be tempted by a high mash and something like T-58 though.