[erockrph]

I just saw the following article from Lallemand regarding thiol biotransformation:

https://www.lallemandbrewing.com/en/united-states/wbwy-newsletter/what-are-thiols-and-their-role-in-hop-biotransformation/

A couple of key takeaways for me were:



This describes beta-lyase activity as a comparison within a selection of Lallemand's yeast strains. Verdant IPA has the highest activity, and other strains' beta-lyase activity are expressed in relation to Verdant. This is helpful for selecting within Lallemand's catalog, but lacks the ability to do an apples-to-apples comparison to other labs' strains (like Cosmic Punch, for example).

The second one was the decreased activity of beta-lyase (an enzyme that liberates thiols from amino acids) in the high-nitrogen environments of beer wort. This makes me wonder if we can increase enzyme activity by using adjuncts to decrease the nitrogen content of wort. It's certainly worth an experiment.

It's good to see another yeast lab start to pay attention here. Omega is doing some really cool things right now, and it's good to see one of the leading dry yeast manufacturers is paying attention (even if they don't end up going down the GMO path themselves).

[ynotbrusum]

Perhaps the manufacturers will come up with a uniform Beta Lyase level expressed in their yeast offerings?  Similar to the hop industry that reflects Alpha Acids and other descriptors with relative measured levels.  It also might answer the lack of bio transformation that many have experienced - I for one have used several of the yeasts from Lallemond that are ranked on the lowest end of the spectrum, without perceiving any bio transformation...but BRY-97 looks to be fairly high ranking on the chart, yet neutral in expression otherwise.

[BrewBama]

I used the Verdant yeast Mark sent me in my NEIPA. I really liked the outcome.


*Disclaimer*: Any comment I add is simply the way I brew beer. There are certainly other ways that can be equally effective which other brewers may contribute. This is what I’ve found that works for me using my equipment and processes so I offer this for your consideration. YMMV

[JoeCap90]

I've done a little bit of research on thiols for my HBC and it seems that there are some yeasts out there like Verdant, London Ale III, etc. that can process thiols, but with enough nitrogen content in the beer, they stop expressing beta-lyase. Cosmic Punch and the other thiolized yeasts seem to have that IRC7 gene switch jammed on and locked in place via genetic modifications *insert CRISPR here* so even though there is "too much nitrogen" in the wort, the yeast continue to express beta-lyase for converting bound thiols into free thiols.

Personally, I don't think it's possible to decrease the nitrogen content of wort. In fact, I'd argue you need that nitrogen content for yeast health and good fermentation. It would be interesting to experiment though using rice and corn to see if there is more enzymatic activity with Verdant, but I don't see myself changing my recipes for hop-forward beers to include more adjuncts for the trace increases in beta-lyase when I could just use Cosmic Punch instead.

[hoursmoggy]

I had a small experiment with nitrogen content with not too big a difference in nitrogen content. And as a result, the test with higher nitrogen content fermentation took place 1.5 times faster than the other experiment. It is exactly what you said.

happy wheels game

[HighVoltageMan!]

The proper level of FAN (nitrogen) in wort is a balancing act. Too much can have staling effect, too little and the fermentation is sluggish, has off flavors and yeast health is reduced.

You can add nitrogen, but about the only way you can reduce it is to replace the malt with a low nitrogen adjunct or a sugar. Don't fret over it, most malts fall with a good range of overall nitrogen (FAN) and it tracks closely with protein levels in malt. More protein means more nitrogen.