Diacetyl Reduction (alpha-acetolactate decarboxylase)

**lamarguy** · 10-22-2009, 09:09 PM

Background: It's the age old problem - how to reduce or eliminate diacetyl in beer...There's a new product on the market (ALDC enzyme) that actively converts the precursor to diacetyl into a high-threshold flavor compound. This effectively eliminates the need for a "diacetyl rest" and reduces the conditioning time since the yeast don't need to later convert the diacetyl themselves.

Problem: No one seems to carry it in the US. AHS used to carry it, but no longer does.

Proposal: Group buy on ALDC direct from the Chinese manufacturer. I contacted the biochem group and they offered a free 2 kg sample, but we would need to pay the FedEx shipping ($60). Besides, 2 kg would last me a lifetime and the shelf life is only one year (refrigerated).

Is there any interest?

Before someone says it, I realize there are existing methods for reducing diacetyl in beer - diacetyl rest, cold pitching (e.g. 45F), high pitch rate, etc. This discussion is about eliminating the formation of diacetyl altogether.

**lamarguy** · 10-23-2009, 03:56 PM

Hmmmm....Nada...

Bokonon · 10-23-2009, 04:10 PM

For $5 or so I would give it a try, but that seems like a bit much to pay for something that really isn't a huge problem for homebrewers. I'm never in a big rush to move stuff out of my fermenters, unlike a pro who has to keep moving product.

**TexLaw** · 10-23-2009, 06:53 PM

No. I have no interest in that. I just use yeast to get rid of unwanted diacetyl, and I'm gonna dance with the one brung me.

TL

Bob · 10-23-2009, 09:02 PM

I concur with Tex. I reduce diacetyl the old-fashioned way: by brewing, not fiddling with enzymes and chemicals.

If brewing chemistry floats your boat, by all means have fun. But realize that this stuff is developed for humongous commercial beer factories to reduce tank time and make more money.

I'd rather practice my craft than put an additive into my beer that doesn't eliminate the brewing-technique problems of diacetyl-precursor formation. Indeed, from your description it sounds like the product just masks the problem, simply raising the concentration threshold above what is required for humans to detect.

So yeah, old-fart brewers probably aren't going to buy in.

Cheers,

Bob

**lamarguy** · 10-23-2009, 09:17 PM

Quote:

Originally Posted by NQ3X

I'd rather practice my craft than put an additive into my beer that doesn't eliminate the brewing-technique problems of diacetyl-precursor formation. Indeed, from your description it sounds like the product just masks the problem, simply raising the concentration threshold above what is required for humans to detect.

Thanks for the comments. One correction - all beers produce diacetyl during fermentation, this enzyme is just a slick method for rapidly accelerating the conditioning process since there will be a significantly reduced amount of yeast by-product to be "consumed".