List of yeasts that do biotransformation

[duelerx]

Any one know a list of ale yeast that can do biotransformation of hop oils?, i know few yeast as US-05 is know for not biotransforming.

 

[Lallemand Eric]

In the Lallemand collection, there are a few strains known to have higher beta-glucosidase activity that promotes biotransformation. These strains are:
- BRY-97
- Belle Saison
- New England
- Koln

 

[Northern_Brewer]

Define what you mean by "biotransformation" - the release of bound aroma compounds from glycosides, conversion of terpenols into more complex flavour compounds, or what? People throw the word "biotransformation" around without specifying exactly what transformation they mean.

Also different hop varieties have different biochemistries that respond differently to the same yeast.

There's no simple list as people are still figuring this stuff out.

In general Saccharomyces don't have a lot of the beta-glucosidase activity you need to release bound hop compounds and so differences between different Sacc strains are a bit hypothetical, it's more a question of which ones are less rubbish than others. It may be more effective to use straight enzyme. Eric mentioned the Lallemand work on their strains summarised here, hopefully it's OK to extract their graph :

Other yeasts such as Brett have more of these enzymes which Scott Janish explored here.

Scott's also seen the apparent transformation of some hop compounds into others as discussed in this paper. He fermented the same Citra/Mosaic/Simcoe wort with Wyeast 1318 and Gigayeast Vermont, and found

I thought the aroma of the 1318 London Ale III beer was slightly similar but turned down about 20% and a little more true to the hops used, meaning less of a yeast derived fruity character blended in with the hops. I never did pick up on a distinct peach character that I often read about for the Vermont strain, but this could be because of the blend of hops used. Rather than a huge sticky orange lifesavers aroma, the London strain was more of an orange sherbert with a slight lemon/lime thing.

Combine that with the Lallemand data and it suggests that the Conan family *may* have more beta-glucosidase but is not so good at transforming citrus flavours into other things.

I've found something similar with a Chinook/Amarillo pale ale - fermenting with Mangrove Jack M36 I got the classic grapefruit you'd expect from Chinook, but the same wort fermented with T-58 had the overall "volume" turned down ~20% but a more complex mix of flavours that was more limey. Exactly what you'd expect if M36 wasn't biotransforming the hop compounds but T-58 was converting a percentage of them into other things. And WB-06 destroyed almost everything, but the mix that was left was more complex still. So it is a balance - you don't actually want *lots* of biotransformation, just enough to be interesting.

Scott's big new thing is the VIN series of wine yeasts from South Africa, although they're not readily available in retail packs.

It's early days, with lots of experimentation to be done.

 

[Lallemand Eric]

Absolutely this is a complex subject and depends on many, many factors including yeast strain, but also hop variety, lot number and storage time as well as the timing of hop additions to name a few. Beta-glucosidase activity is one of several mechanisms of hop biotransformation and we are just beginning to scratch the surface.

 

[Northern_Brewer]

@Lallemand Eric, given that Windsor and T-58 are pretty closely related, have you guys seen any signs of Windsor changing terpene profiles?

 

[Parrothead1]

http://scottjanish.com/examination-...s-for-achieving-maximum-hop-aroma-and-flavor/