At a glance
DKO stands for Diacetyl Knock Out
| What it does |
Expresses ALDC inside the yeast cell, blocking diacetyl where it starts.
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Why it matters
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Skip the diacetyl rest, turn tanks faster, and shut down the diacetyl produced by hop creep.
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Best For
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Heavily hopped beers prone to hop creep, lagers, and any brewery optimizing tank time and consistency.
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Stability
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Holds across generations. No buying exogenous ALDC every batch.
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The problem
What is diacetyl?
Diacetyl is an organic compound that gives beer a buttered popcorn or butterscotch aroma. It’s generally unwelcome, except at low levels in a handful of English and Czech styles. It’s a natural by-product of fermentation, but one that still needs to be cleaned up.
So how does diacetyl form in beer? During the cell growth phase of fermentation, yeast produces diacetyl precursor alpha-acetolactate as part of amino acid synthesis. Some of that alpha-acetolactate will seep through the yeast cell walls, oxidize, and turn into diacetyl. Afterward healthy, active yeast will reabsorb that diacetyl and reduce it to a compound that’s flavorless in beer. Problem solved.
However, yeast in a rushed or less-than-healthy fermentation won’t be able break all of those compounds back down, leaving behind buttery diacetyl. Hop creep from late dry-hopping can also lead to diacetyl formation. Hop enzymes release more sugars to yeast in a more stressful, nutrient-deficient environment, which can make leave the yeast slow or unable to clean up after themselves.
How do you make sure diacetyl doesn’t end up in your beer? The answer is another enzyme: ALDC.
The solution
How does ALDC affect diacetyl?
ALDC (alpha-acetolactate decarboxylase) enzyme converts alpha-acetolactate, the precursor to diacetyl, straight into the flavorless compound acetoin.
The issue with added ALDC enzyme is that it’s only operating outside the yeast cell walls and it’s pH-sensitive (it fades as fermentation drops below a pH of 5). It’s also only proactive, which means it can't clean up diacetyl that has already formed. This leaves the beer vulnerable to diacetyl exactly when hop creep bites.
That leaves a lot to chance, so we engineered the DKO solution.
The tech
How does DKO work?
DKO technology gives a strain the ability to express ALDC and keeps the reaction inside the cell. ALDC converts alpha-acetolactate to acetoin before the cell excretes it, and it keeps working through late fermentation, when dry-hop enzymes free fresh sugar and restart the whole cycle. It is also genetically stable across generations, so the benefit is consistent with each batch.
The strains
Choose your own adventure
At the moment, we have 11 strains with DKO technology to choose from. Do you see your house strain in there?
| West Coast+ | "Chico" in its best form. DKO and Lumina deliver clean, crystal-clear beer without lingering diacetyl or haze. |
| Point Loma+ | DKO and Lumina address cellar hangups directly, making this a strong house strain candidate, particularly for heavy clean IPA producers. |
| British V+ | The ALDC-expressing gold standard for hazies. |
| Mexican Lager+ | DKO makes our cleanest lager strain ever so slightly cleaner. Stellar for West Coast IPAs. |
| DIPA+ | All the reliability of DIPA, none of the diacetyl spikes during hop creep. |
| Extra Special+ | Drops remarkably clear, leaving behind nuanced esters with a dash of residual sweetness. |
| Kolsch II+ | Snappy, hop-forward, and clean. Genetically haze-positive, dry hopping triggers stable haze, while DKO keeps diacetyl out of the picture. |
| German Lager+ | Sports a famously versatile malty profile with slight esters at a wide fermentation range. |
| Bayern Lager+ | The famous profile lays the groundwork for traditional lagers such as helles, kellerbiers, and pilsners. |
| Little DIPA+ | A Thiolized version of the "Conan" strain without the diacetyl hangup |
| Vossa Nova | A Thiolized version of Voss Kveik, known for reliable haze and tangy citrus notes across its broad temp range. |
p.s. we can also engineer your house strain with DKO technology.
The data
Read the sensory
Three scenarios, three DKO strains, one result: the parent strains exceed the diacetyl sensory threshold, the DKO versions don't.
Even without dry hopping, diacetyl still forms as yeast becomes stressed and tired late in fermentation. Extra Special climbs near 700 µg/L early and slowly works it back down; Extra Special+ stays flat near zero the whole way.
DKO yeast are more effective against dry-hop-induced diacetyl. With a dry hop in play, West Coast Ale I spikes well past the sensory threshold on day 8, while West Coast Ale I+ holds beneath it through day 14.
In the lager, diacetyl from the parent strain peaks near 1,000 ppb mid-fermentation and requires a rest. German Lager I+ never crosses the threshold.
Next Steps
Try a simpler path
We suggest finding the strains you're familiar with and utilizing the engineered version with DKO. It's the first step into modernizing production and directly addressing both quality and operational blockers.
Stay bubbling,
The Omega team