Thiolized yeast unlocks tropical thiol aromas from hops and malt

At a glance

What is Thiolized yeast?

An explanation

Why can't you smell most thiols on their own? 

In short, you need an engineered strain to unlock most thiol expressions.  

The major thiols released by Thiolized yeast are 3-sulfanylhexan-1-ol (3SH) and 3-sulfanylhexylacetate.

These are extremely potent compounds at parts per trillion levels, and add the signature passionfruit, guava and grapefruit notes of New Zealand hops and Sauvignon Blanc wine.

In wort almost all of that thiol sits bound to amino acids in a non-aromatic precursor form, outnumbering the free, smellable version by about a thousand to one. You can't taste it yet because ordinary brewing yeast barely cleaves it.

Function

How does it actually work?

It comes down to one enzyme — a carbon sulfur lyase enzyme — that snips the bound precursor and sets the free thiol loose. We started with IRC7, the yeast's own β-lyase gene. Most brewing strains carry a truncated copy, or switch it off in the high-nitrogen wort typical of a hazy IPA, so we rebuilt the promoter to keep it active and used CRISPR/Cas9 to move a working, always-on version into British Ale V. That became Cosmic Punch, the first Thiolized strain.

For more lift we added PatB, a bacterial carbon sulfur lyase from Staphylococcus hominis (a microbe that lives on human skin), which drives a far larger thiol burst. Finished thiol levels are elevated further and land within the natural range of Sauvignon Blanc and tropical fruit.

The strains

Choose your own adventure

You have six Thiolized strains to choose from. Each strain has its own aromatic signature and way of presenting its character. For each Thiolized strain, you can expect the same fermentation behavior, specs, and presentation as the parent strain. 

The data

Read the sensory

Nuanced Approach

Dialing in complementary thiol expression

Thiols produced in fermentation can be balanced out with a heavier dry hop dose, leading to an intensely hoppy, thiol-forward beer.

Avoid adding extra thiol precursors via mash hopping or grape-derived products.

Utilize adjuncts in the mash bill such as oats, wheat and/or rice because they have little, if any, thiol precursor.

Blending Thiolized strains with the parent strain can be a great method for halving or even quartering thiol levels in the finished beer. This service is free. 

If you're looking for a hazy house strain, Cosmic Punch adds nuanced thiol profile that elevates hop character. 

Dominant Approach

Getting maximum thiol expression

Oddly enough, dial back hop load. Thiols produced in fermentation can be balanced out with a heavier dry hop dose so if you want more dominant thiol expression, tailor back hop volume. 

For extra thiol precursor, give Propper Phantasm a whirl. 

Avoid utilizing adjuncts in the mash bill such as oats, wheat and/or rice because they have little, if any, thiol precursor. Simplify our grist and bulk up on barley base malt to maximize precursor.

Next Steps 

Keep the ideas flowing

There's more work to be done with understanding thiol expression. We'll be publishing research updates as we unravel new findings and insights. In the meantime, we're here to be helpful. 

Stay bubbling, 

The Omega team