Hey everyone, I'm currently fermenting my first lager, an octoberfest, and I'm wondering when to do the diacetyl rest. It is currently sitting in my primary at right around 55 degrees and has been fermenting now for 9-10 days. The airlock activity has slowed but not stopped. I understand that I need to take a hydrometer reading, but I really don't want to open the bucket for a sample until its necessary. Any advice would be appreciated.
First lager and when to diacetyl rest
- Thread starter pharmer
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It sounds like it could be about time. I'd take an SG and if it's 1.022 or lower, do the diacetyl rest now.
Personally I don't like to open my bucket either. If it's a lower gravity lager, I'll start the diacetyl rest when the bubbling slows. Higher gravity, I bite the bullet and take a reading.
Okay, so I brought the fermenter up to temp and there was no noticeable increase in airlock activity. Is this normal? Should I rack now to secondary and allow to remain at room temperature for awhile longer or start bringing the temp down for lagering?
If you have previous experience with diacetyl, as most lager brewers (unfortunately including myself) do, you should be able to detect it in the sample you pulled. A diacetyl rest is not always necessary (especially if you pitched enough yeast and had a good, vigorous fermentation), so if you don't detect it, chances are you are in the clear. For future reference, raise your temp for the d-rest when you are something like 8 or 10 points above expected OG. There really isn't much danger to removing the lid from your bucket to take a hydrometer reading.
Unfortunately, being a new homebrewer, I do not have any experience with diacetyl. I did not detect any buttery or butterscotch flavors, but I understand that many inexperienced people cannot detect diacetyl. If there is diaceyl present, would the taste become more pronounced over the course of the lagering period?
wheatgerm
Well-Known Member
I remember John Palmer saying to do the DR when you see the krausen begin to fall back into the wort. Doesn't sound very scientific, but it seemed to work in my case. There was enough action left to give me roughly a 48 hour DR, even though most of the yeast had flocc'd by then. YMMV.
One sign of diacetyl is a "slick" or "oily" mouthfeel. It sort of "sticks" to your tongue. If you feel that (even if you don't taste butter), the diacetyl rest needs to be extended.
Remember that it won't hurt to do a diacetyl rest as a matter of course, whether strictly needed or not.
If there is ANY hint of diacetyl in the sample, even if it's just a slightly oiliness, it will get much worse with time and with lagering.
Remember that it won't hurt to do a diacetyl rest as a matter of course, whether strictly needed or not.
If there is ANY hint of diacetyl in the sample, even if it's just a slightly oiliness, it will get much worse with time and with lagering.
Thanks to all for the replies, and now for another question. I just racked to my secondary for lagering, and it seems that may have slightly awakened the yeast. Should I allow some additional time for the yeasties to work, or start the lagering now?
Are you sure it's fermentation and not just CO2 coming out of solution because you warmed up the beer?
I assume you raise the temp, so I'd guess it's just a release of dissolved CO2.
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