Sanity restored - thanks to HBT and a diacetyl test

I finally forgot to do a d-rest. Life has been crazy, and it just slipped my mind. I've done a d-rest for every previous batch, and I'm making my very excellent rye IPA, so you can imagine there was some panic when I realized I had cold crashed without first performing my usual d-rest. I took a sample from the bucket, and *gasp* it even felt slightly oily in my mouth. After some research, I found the instructions for a diacetyl test. Twenty minutes later, there is definitely no diacetyl in my beer, and I am resting easy.

Notes:
My primary fermentation lasted 3 weeks before the cold crash. I pitched the yeast at ~50 and let the temp rise on its own. A blowoff began the next day.

For the d-test, I heated to ~140 for 20 minutes. The first whiff of the beer was really potent, and I was not prepared for that. It was almost boozy - like hot rum or something. BUT there was definitely zero butter to it. If there had been, it would have been impossible to miss using this test. A taste of the hot beer also yielded no butter, nor was the sample oily. I think it was all in my head.

Thanks HBT!

If diacetyl forms during primary fermentation and if it is caught early enough, it can be removed by jacking up the temp a few degrees and by extending the length of time the beer will be in the fermenter. The yeast needs to be healthy enough to do the job. If diacetyl is formed after primary fermentation it can be temporarily removed. Diacetyl can return later on and it gets stronger as time goes on. With using good yeast, enough of it and wort containing enough nutrients and oxygen to support yeast, diacetyl rarely becomes an issue in ale or even in lager. Ale left in the primary for two weeks is enough time for the yeast to clean up diacetyl. Sometimes, it is better to clean up the brewing process if a diacetyl rest becomes a normal part of the process, especially when producing ale. Otherwise, an enzyme can be added that eliminates the diacetyl precursor. Hopefully, the the rest cleaned it up for good.

Wait, you heated your fermented beer?

mmb said:

Wait, you heated your fermented beer?

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Yep, to do the diacetyl test but it's only a small amount.

Yooper said:

Yep, to do the diacetyl test but it's only a small amount.

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Ahhh, I read test as rest.

mmb said:

Ahhh, I read test as rest.

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Well, that would definitely explain your reaction!

I'm someone that can pick up diacetyl in relatively small quantities, so I haven't ever done a test for it, but it would work very well for someone who doesn't have a real great feeling for diacetyl and what it is.

The test worked great. I normally do a d-rest just out of habit. It's easy to do and it also helps assure full attenuation. This was honestly the first time I haven't done one. It's been a crazy few weeks. So, I think my concern was somewhat justified, and I'm really glad there was an easy test. If there had been diacetyl in there, it would absolutely blast you in the face using the test.