Is Brett Predatory?

[statseeker]

This is a two-fold question:

1. Does brettanomyces only feed on dead and decaying yeast?

2. Do you think that brett would eventually become the only yeast in a yeast cake of a Sacc. strain and a brett strain?

The reason I ask is that I have a yeast cake (plus about 1 inch of stout) of 9097 Old Ale yeast and now it has a pretty nice pellicle on it after I've left it for about a month without washing. I have a feeling the pellicle is from the brett feeding on the dead yeast and maybe some left over unfermented sugar. I want to rewash this yeast and maybe add a portion of the washed blend to a Sacc. fermented brown later on in its life.

 

[jmo88]

I don't believe that's the issue. More likely the pellicle is a result of oxygen being introduced to the beer after racking.

 

[hopsalot]

too my knowledge, NO, brett does not feed on dead/dormant saccharomyces. Brett can consume much smaller sugars, therefore left over, that Saccharomyces cannot. Brett can eat unfermentable dextrins as well. Brett is chowing down on the left over fermentables not saccharomyces.

I do not think that brett would eventually become the only yeast in a yeast cake of a Sacc. strain. I will do some research though

 

[strat_thru_marshall]

1. No
2. No

For sure no to both questions.

The pellicle forms to protect the yeast from oxygen, when you transferred the beer out of the carboy, the added air in the headspace caused the yeast to form the pellicle.

 

[Wernerherzog]

Brett does indeed eat dead yeast cells, or rather nutrients left in their dead "bodies", see pg. 166 in wild Brews. Also, pg. 174 where Sparrow compares the different Brett character in Flanders and Lambics by the fact that the production of Flanders beers involves racking off the original Saccharomyces relatively early on and the fact that Lambics continue to sit on the original yeast cake, providing more nutrients to the Brett when it starts to run out of residual sugars/sugars unfermentable by Sacc.

To answer your question, barring other variables, the life of Brett will be much longer than Sacc. since it can eat a lot more things than Sacc. can. I don't know whether this means it will totally take over a cake though.

 

[ReverseApacheMaster]

I think it would take a very long time before the brett would completely consume all the sacc. If you repitched on the cake under more normal circumstances the sacc would wake up, reproduce and eat sugars, reestablishing its population in the cake.

 

[smokinghole]

1. Brett doesn't only consume the dead yeast but it will consume nutrients that remain in the dead cell walls and what was released when they died.
2. I highly doubt all the sacch would be dead leaving only brett. I think that would be more pH dependent than based on food availability. You have to remember that yeast have been extracted and used from pieces of hardened amber.

Brett is better suited for survival in already fermented beverages like wine and beer. I think in the laboratory brett has been taken up to 12%abv but has been found in wines higher than 14%abv (can't find the paper that has the data). So it can survive in fairly low pH where sacch would surely be dead.

 

[statseeker]

Cool. Most brewers and yeast scientists say not to repitch on a brett blend because the funk will be magnified. I dont know if I mind that so much in THIS case just by the smell of the yeast cake. It smells sort of lightly like cherry pie and stout. Tells me the Brett strain is likely lambicus. A brown will be delicious with the blend. I was just curious if there was any evidence the Brett feeds on the dormant yeast. By the answers here, it doesnt, which is good with me.

 

[ryane]

Cool. Most brewers and yeast scientists say not to repitch on a brett blend because the funk will be magnified. I dont know if I mind that so much in THIS case just by the smell of the yeast cake. It smells sort of lightly like cherry pie and stout. Tells me the Brett strain is likely lambicus. A brown will be delicious with the blend. I was just curious if there was any evidence the Brett feeds on the dormant yeast. By the answers here, it doesnt, which is good with me.

If I remember right, contrary to what it seems the brett in 9097 was confirmed to be brux

 

[statseeker]

http://www.wyeastlab.com/hb_yeaststrain_detail.cfm?ID=147

http://www.wyeastlab.com/PC4Q2010.cfm

That's from Wyeast's website. I'd be surprised if it's brux. The character of the smell alone is way off. If it is though, maybe I stressed it into producing those characteristics. Worth trying again I think.

These questions beg another question for me:

If I were to make a starter with only dextrins and sugars that Sacc. couldnt eat, do you think it's possible to isolate the brett strain from the sacc. strain just from fermenting with those dextrins? It would seem to be slow but I think it would work. I dont think the Sacc. would be activated by the starter and would likely sink to the bottom just dormant. But the brett might come out and eat.

This seems like a time for an experiment.

 

[smokinghole]

You can isolate the brett from the sacch using some media. One in particular is Lins Cupric Sulfate Medium. It contains cupric sulfate and the media will kill off MOST brewing strains of yeast. If you wanted to isolate the brett you would just streak it on the plate pick the best looking colony and then transfer that colony onto a malt sugar enriched agar plate. From there you could grow in liquid media. The only true way to identify the strain of brett would be through some DNA sequencing most likely.

The other thing to consider just like with the PC yeast cultures and blends is the possibility that the brett they used is a strain they have on freeze that is not generally available. If you look at yeast culture collection sites you can find 5-6 different strains of Brett b. or Brett N.

 

[ryane]

http://www.wyeastlab.com/hb_yeaststrain_detail.cfm?ID=147

http://www.wyeastlab.com/PC4Q2010.cfm

That's from Wyeast's website. I'd be surprised if it's brux. The character of the smell alone is way off. If it is though, maybe I stressed it into producing those characteristics. Worth trying again I think.

These questions beg another question for me:

If I were to make a starter with only dextrins and sugars that Sacc. couldnt eat, do you think it's possible to isolate the brett strain from the sacc. strain just from fermenting with those dextrins? It would seem to be slow but I think it would work. I dont think the Sacc. would be activated by the starter and would likely sink to the bottom just dormant. But the brett might come out and eat.

This seems like a time for an experiment.

Im pretty sure it was actually confirmed by Wyeast to be brux, trust me I thought it was L too for a long time, but after aging it definitely has more of a brux character

 

[statseeker]

The things you learn....

The agar plate thing seems like a lot of time and work. Worth a try though. I'll see what my budget is. Would the dextrin fermentation thing work at all? Is it even worth trying?

 

[smokinghole]

The problem with the dextrin fermentation method is that you will still have Saccharomyces mixed in with the Brettanomyces. The only way to truly select for the Brett would be to kill off the Sacch. Also the media cost for one can of that LCSM (lins cupric sulfate) is about $250. I'm not sure you can get it in smaller quantities.

 

[statseeker]

Ouch. Maybe it'd be better to just buy the brett on its own or do an agar plate streak. If it's brux I might end up selectively mixing it with different strains of Sacc.

I want to do a lambicus fermentation with S-04 as the primary fermenter. I think the mixture would make a great brown or porter if I leave enough fermentables for the brett.

 

[smokinghole]

Next time I have LCSM plates on hand I can open a bottle of beer made with the old ale blend and isolate the brett. Then I'll grow up into about a 1L starter. I'll split that so I have it isolated on hand and one for you. You'll have to grow it quite a bit more but I can centrifuge the starter to get a nice dense pellet of brett at the bottom.

 

[ReverseApacheMaster]

For $10 you can buy a pure strain of brett.

I'm just saying...

 

[statseeker]

The only thing is: We're not 100% sure which strain it is. I just contacted Wyeast to find out just to double confirm whether or not it's Brux. I cant let this doubt go, no offense to ryane, I just want to know for sure.

Smokinghole: Thank you so much for offering to do that for me. I'll gladly take you up on that and pay shipping and handling and all that if we find out that the strain they use in the blend is not commercially available on it's own or if it somehow different from the commercially isolated strain. I think that is reasonable for both of us, so you dont waste your time and energy (and money, depending on cost) on this and I dont unnecessarily inconvenience you.

 

[smokinghole]

I do yeast testing on a regular basis to check for contamination. I haven't made plates in a few weeks but I will be making plates on a weekly basis again real soon. So I will get this streaked and grown in a month or so. No cost to me because sometimes the LCSM plates don't get used up so instead of throwing them out I'll just streak on them. If they're left too long the plates will supposedly inhibit even wild yeast growth which for my case gives false negatives.

I'll let you know.

 

[statseeker]

Interesting. I'll have my PM line open. Thanks a million times man.

 

[ryane]

The only thing is: We're not 100% sure which strain it is. I just contacted Wyeast to find out just to double confirm whether or not it's Brux. I cant let this doubt go, no offense to ryane, I just want to know for sure.

Hey no worries, independent verification will be great, I couldnt find the thread that discussed this, I wanna say it was the greenboard but it could have been bbb

 

[jmo88]

The only thing is: We're not 100% sure which strain it is. I just contacted Wyeast to find out just to double confirm whether or not it's Brux. I cant let this doubt go, no offense to ryane, I just want to know for sure.

Isn't clausenii the strain that was isolated from English stock beers? That'd make sense if 9097 used that strain, but I don't see it in Wyeasts catalogue, so maybe they're using something else. I haven't tasted my old ale enough to have any personal observations.

 

[statseeker]

I think yes that is the one.

I found something EXTREMELY interesting searching around on wikipedia (I know, accuracy would dictate that wikipedia not be used, but since this isnt a dissertation, we'll go with it). Turns out Brux and Lambicus are genetically IDENTICAL. Abstinens and Custerianus are also identical. And Anomalus and Clausenii? Also identical. The types have evolutionarily built in redundancy. I think that's so that they can colonize with each other in the wild, thereby increasing their chances of survival upon being separated. Fungus is so interesting.

 

[smokinghole]

Clausenii is the strain that was isolated from the stock beers. It would make sense but it seems everyone kept getting reports that it was not clausenii in the blend.

The brux and lambicus may be almost identical but different strains can produce different results due to genetic drift and mutations. That's why the Wyeast strains are different than the White Labs stuff. Also the Russian River "Funky Bunch" I think were purchased strains from White Labs but he exposed them to his own selective pressures like higher alcohol or high temperatures and developed his own house character with them.

 

[statseeker]

Brux and lambicus and the other 2 twins are identical. Not almost, but DNA identical. Granted, they may have different evolutionary characteristics, but at a genetic level, they are the same organism.

"Examination of the Mitochondrial DNA of the genus Brettanomyces showed identical genomes in three pairs of species: Dekkera bruxellensis/Brettanomyces lambicus, Brettanomyces abstinens/Brettanomyces custerianus and Brettanomyces anomalus/Brettanomyces clausenii. It is suspected that the genus Dekkera has similar taxonomical redundancies."

http://en.wikipedia.org/wiki/Brettanomyces_Claussenii#cite_note-3

I find all of this extremely interesting and quite puzzling all at the same time. But it kind of feeds into our discussion about whether the Old Ale strain from Wyeast is Brux or Lambicus. If they are identical (genetically anyway), it makes sense that there might be such a similarity that it breeds debate as far as which strain is the one in 9097.

 

[ryane]

I think we need to be careful when speaking of the strains as identical. Just because DNA is identical doesnt mean they function the same. It really depends on which enzymes and other proteins are expressed that determines the end effect. This is most likely why they have been labeled as different.

 

[smokinghole]

I'm no geneticist, but I do play a senior year biotechnology student during the week. The genes that are used to identify various species is not the entire genome. There will be coding and non coding genetic differences. Some of the coding variations can be multicopy genes that code for the same protein. When that happens the protein is produced more frequently. These multicopy genes will control the metabolic byproducts of each separate strain. With that being said that is likely the reason white labs brett L has a more "horsey" flavor than Wyeast's Brett L. So while they will be genetically similar as a species there will be genetic differences that allows each strain to have its on independent attributes. The problem with identifying the genes responsible for the attributes is not that the genome is not small. The Saccharomyces cerevisiae has more than 12million base pairs in length with 5,770 identified genes. Brettanomyces spp. is probably very similarly sized with less identified genes because there has not been a whole lot of research focused on brett.

So while some genes will be identical many will not be identical. That's why, as said above, breweries can basically induce house character over time. They will expose the yeast to specific environmental conditions that will force certain genes to become expressed stronger than others.

 

[statseeker]

See? This is a pretty cool discussion. I've never really gotten this in depth with brett. I've brewed with it, but never really heavily researched it. All of this is pretty fascinating. Makes me want to purchase several more carboys just for the purpose of aging brett-laced beers and culturing brett strains. I'm SUPER interested in Al's Bugfarm just to get some of the brett mixes.