CBC-1 and esterification

[brewNYC]

I have been using CBC 1 for bottling yeast on my last half-dozen batches. I love the results! My carbonation is always spot-on, and quick! I also noticed that my hazy beers are less (ahem) digestivly problematic, my guess would be because CBC-1 kills the other brewing yeast, then drops like a brick to the bottom of the bottle.

I am wondering, though, how well CBC-1 works for extended aging in the bottles. For big barlywines and Belgians, I really count on the bottling yeast to do some esterification of the higher alcohols that are always present, unless you bulk age for a really, really long time before bottling. Since CBC-1 kills the primary brewing yeast, then only consumes simple sugars, does it not continue to perform esterification after consuming all your priming sugar? If so, it might be better to use a fresh batch of brewing yeast at bottling instead of CBC 1 for big beers.

 

[cactusgarrett]

For what it's worth, I use CBC-1 to bottle my sours (8-10% abv) - which typically age for 1+ year. I actually have started to do an acid shock starter with it, as I wasn't thrilled with how it behaved at very low pH, regarding how long it took to fully carb. I also haven't noted any THP, fwiw.

 

[mediant]

While yeast strain is an important factor for ester and HA production in bottle refermentation (see here), I don't think it plays any significant role during aging - except for ester degradation via esterase activity. Major Belgian and German beer producers pasteurize ales to achieve flavor stability, others use minimal cell count - all this to prevent yeast autolysis leaching esterases. You may find this presentation interesting too.

To summarize - bottled yeast both produce and break the esters down, profile and balance is strain-dependent. Most important is to bottle with cell count as low as possible (Doemens recommends 1-5x10E6 cells/ml) if you want the flavors to survive during prolonged aging...

 

[brewNYC]

I don't think it plays any significant role during aging - except for ester degradation via esterase activity

Interesting- it seems conventional wisdom would disagree - hence the long recommended bottle aging for big beers. But conventional wisdom isn’t always true.

I noticed the article noted that bottle conditioning increased higher alcohols, rather than decreasing, but also noted that HA’s remained below the perception threshold at all times. However, I note that the researcher brewed a small, simple beer with a short bottle conditioning period, so this is not surprising.

Do you know if anyone has done a similar analysis on something like a Barleywine or Belgian quad aged for 6+ months?Conventional wisdom is that these beers inevitably have a lot of HA when they are green, due to the strain put on the yeast, but “clean up” in extended aging, both in secondary and also in the bottle. I would love to see someone measure the actual HA levels of a big bottle conditioned beer to see if this is true..

 

[mediant]

Interesting- it seems conventional wisdom would disagree - hence the long recommended bottle aging for big beers. But conventional wisdom isn’t always true.

There's no contradiction here, as transesterification plays important role in aging, especially wood aging or sour beers, when free acids replace original acid within some common esters, creating new flavors. It happens without yeast though...

 

[brewNYC]

There's no contradiction here, as transesterification plays important role in aging, especially wood aging or sour beers, when free acids replace original acid within some common esters, creating new flavors. It happens without yeast though...

True, but my understanding is that Transesterification is the conversion of one ester to another (it used to smell like banana, now it smells like apples, etc), whereas esterification is the conversion of alcohols to esters (it used to taste like solvent, now it taste like bananas). Transesterification does not require yeast, but esterification does. See articles below.


http://www.professorbeer.com/articles/esters.html
http://sourbeerblog.com/understanding-esterification/

So, I guess there are two questions now - does significant conversion of fusels to esters happen during bottle conditioning, or is that a myth? And the original question, does CBC-1, with its limited diet of only glucose and maltose, perform esterification as well as a typical yeast strain which also slowly munches on minute amounts of leftover non-simple sugars in the bottle?

 

[brewNYC]

For what it's worth, I use CBC-1 to bottle my sours (8-10% abv) - which typically age for 1+ year. I actually have started to do an acid shock starter with it, as I wasn't thrilled with how it behaved at very low pH, regarding how long it took to fully carb. I also haven't noted any THP, fwiw.

Interesting- why use CBC-1? I thought Brett was the ultimate bottle-conditioning yeast, if you like the flavor..

 

[cactusgarrett]

Reliable, quick carb. Beer has tons of flavor already.

 

[sweetcell]

Interesting- why use CBC-1? I thought Brett was the ultimate bottle-conditioning yeast, if you like the flavor..

bottle conditioning with brett can take months, and you run the risk of THP. use of CBC-1 or some other sacch mitigates both of these issues.

 

[brewNYC]

bottle conditioning with brett can take months, and you run the risk of THP. use of CBC-1 or some other sacch mitigates both of these issues.

Good to know. I’m not a sour beer guy, but I’ll pass this info along to my brewing friends..

Gotta drag back to the original question. Does anybody know how well CBC-1 makes esters out of fusels, compared to other yeasts? I’m starting to think this whole fusels-to-esters by esterification thing might be a myth, though a widely held one..

 

[mediant]

True, but my understanding is that Transesterification is the conversion of one ester to another (it used to smell like banana, now it smells like apples, etc), whereas esterification is the conversion of alcohols to esters (it used to taste like solvent, now it taste like bananas). Transesterification does not require yeast, but esterification does. See articles below.

http://www.professorbeer.com/articles/esters.html
http://sourbeerblog.com/understanding-esterification/

So, I guess there are two questions now - does significant conversion of fusels to esters happen during bottle conditioning, or is that a myth? And the original question, does CBC-1, with its limited diet of only glucose and maltose, perform esterification as well as a typical yeast strain which also slowly munches on minute amounts of leftover non-simple sugars in the bottle?

I'm not sure we're on the same page here. As with any fermentation, there's some yeast-driven esterification during bottle refermentation, as the studies I linked earlier prove. After that short fermentation period, the role of yeast is minimal, but the negative impact due to autolysis may be substantial if the cell count at bottling is not well controlled.

Beside yeast driven ones, there are many other processes happening during beer aging, e.g. higher alcohols being oxidized by melanoidins. You may find these interesting:
https://cdn.uclouvain.be/public/Exports reddot/inbr/documents/presentation-daan-saison.pdf
https://draftmag.com/required-reading-the-chemistry-of-beer-aging/
http://www.lambic.info/images/f/f3/Vanderhaegen2007Agingcharacteristicsofdifferentbeertypes.pdf

 

[brewNYC]

What I’m gathering, from these posts and articles, is that yeast do produce esters from alcohols, so fusels can reduce during fermentation. I don’t see any evidence that fusels decrease during bottle conditioning, though, so I am starting to think this is a widely held myth (certainly not the only one in the home brewing world). With that said, it does appear that bottle conditioning does have a number of other benefits that have nothing to do with yeast or higher alcohols.