What's the D with Brewzyme-D?

Category : General
Date : June 11, 2024
Author : Chris White, Ph.D
Brewzyme-D is a new White Labs product that’s designed to be added on the cold side. This ALDC enzyme reduces the flavor of diacetyl and makes more consistent fermentations in shorter times.

It has a renewed interest right now because of dry-hop beers and hop creep. It was something that people liked for lager beers, but because of the propensity of cold fermentations and lager yeast to make more precursors, that would turn into diacetyl later. For ales, when you dry-hop a beer and hop creep happens, then another little mini-fermentation happens, making more precursors, making more possible diacetyl later.

So people are interested in reducing that and reducing tank times, and it’s an example of new things, like nutrients and enzymes that people are adding with the yeast pitch, adding on the cold side. And with Brewzyme-D and dry-hop beers, it will be added again at the dry-hopping stage.

WLE4900 Brewzyme-D



Another advantage of the enzymes that White Labs produces, like Brewzyme-D, is that we do the microbiology testing in our labs to make sure they’re clean to add on the cold side because you’re now post-boil, so you want to make sure that you’ve got something that’s not going to cause another problem with contamination. Brewzyme-D is thoroughly tested and sterilized for that and it’s convenient to use. Brewers in the past didn’t use to add anything else but yeast. We added our nutrients in the kettle or whirlpool. Everything was on the hot side, but now people have realized that we’re losing a lot of those nutrients when we add them.

Brewzyme-D is an example of an enzyme that can be added on the cold side because adding it to the hot side would endanger it; the enzyme would unfold and denature. So, the most important part of Brewzyme-D is how it’s added to the fermentor. It must be added in-line or in the beginning, in the cone, so that it mixes thoroughly with the wort coming in. 


It’s really important that enzymes and nutrients get thoroughly homogenized and mixed because it’s not like yeast, where people can add it in different ways. It still works because you’re making around five times more cells from the cells you add.
Brewzyme-D - Process
With an enzyme, it must find its substrate for it to work. Because an enzyme is not growing, it has to be well-mixed into the wort to increase surface area and effectiveness.  I was talking to a brewer who uses Brewzyme-D, adding through the top hatch, and they had a dry-hop IPA that still had higher diacetyl levels. It’s a good example to show that even if you use the right products, you still must use a proper procedure every time for it to work properly. Some of the enzymatic reactions will happen in fermentation, but not as much as you would think. 
We recommend adding it directly into the fermentor before knockout to ensure adequate homogenization, as well as adding it after each dry hop, as hop trub can pull some of the enzymes out of suspension. Since the solution is pre-sterilized, be sure to use proper aseptic technique when handling. 

Calculate Your Optimal Brewzyme-D Dosage for Your Brew

Brewzyme-D Dosage


  • Pro (1L, 10L): 15-20mL/hL (0.84 BBL)
  • HB (10mL): 10mL/ 20L (5 Gal)


Activity Range: 

pH: 4.0-7.0
Temperature: 50-104°F (10-40°C)


Temperature: 32-50°F(0-10°C) Do not freeze.
Location: Sealed and away from sunlight.
Shelf Life: 18 months from manufacture date, when stored as recommended.

Measuring diacetyl would be great if you could do that! But the only way you can really measure it is in a gas chromatograph, a GC, and big breweries have GCs for that sole purpose. They don’t transfer or cold crash a beer until they have a verified total diacetyl number. Usually, people are looking for under 60 ppb, but it can range from beer styles to different packaging types. 

An alternative breweries can do to test for diacetyl is the forced diacetyl test, which involves heating the beer, trying to force all the precursors to the diacetyl, and then doing a smell test. It's not perfect and can be subjective, but it is an easy and quick way to know whether the beer is finished or if something is hiding as a potential diacetyl.

Forced Diacetyl Testing

If you don't have a GC and want quantitative numbers to correlate, you can always send it to White Labs. But if you don’t want to do that, you need to perform the forced diacetyl test at least.


Diacteyl (As-is) Analysis
Diacetyl (Total) Analysis



Diacytel in Dry in Hopped Beer
There are multiple ways to keep diacetyl low in dry-hop beers. One is yeast health, two is ALDC or Brewzyme-D, and the third is really watching that pH. One must watch their pH because anything over 4.6 is not compliant with FDA guidelines for fermented beverages in the United States, yet a low pH actually inhibits Brewzyme-D. So that’s not good either. When one dry-hops, the pH rises, so starting at a pH of 4.4 or even lower is preferred. This low of a pH gets close to where it starts inhibiting Brewzyme-D as well, but that’s the balance that you need to really watch.