Diaceyl Rest Hot Mess

[syke0021]

I'm almost too embarrassed to post this, but view it as an opportunity to learn more from my mistake(s).

I brewed a huge doppelbock for a competition that required me to have an OG over 1.100. The OG ended up at 1.114 before I hit it with a few minutes of oxygen and repitched an entire yeast cake of Wyeast 2124 Bohemian Lager yeast from a 1.056 Festbier.

Everything was going great. Fermenting at 50 degrees, I had a full krausen with 12 hours and a blowoff hose was needed within 20 hours. For me, this was unprecedented lager activity. Yeast activity was vigorous for 5 days before beginning to slow.

I had been concerned that I the beer would stall out too soon due to the high alcohol content. I wanted to allow the yeast activity to raise the temperature to 65 for a diacetly rest and have the yeast work for 48 hours while still slightly active. Thus, when I saw reduced activity this morning on my way out the door, I made the call to turn off the temperature control unit. Tonight, after 12 hours away, the temperature had risen to 58 degrees and when I moved the carboy out of my fermentation chamber, I realized the yeast was much more active than I previously thought.

At this point, I did what I should have done in the morning, if time allowed, and took a hydrometer reading at 1.060. This is only about 60% of the way there when typically I wait until I'm 75-80%. Because I was still within the 2124's temperature range, I decided to return it to the fermentation chamber and go back down to 50 degrees for a few more days(until at 1.042). I'm fearful that reducing the temperature at this point may have even more of a negative effect on the yeast and shock them into inactivity, but don't want to be at 58+ degrees either.

So, obviously I've learned my lesson and will never again assume I'm ready for a diacetyl rest without a hydrometer reading. If anyone has any idea what I can expect from this hot mess, I'd be happy to hear about it. Otherwise, I'll just update the thread with what happens next...

 

[behindthetimes]

I think you'll be absolutely fine. At 60% I wouldn't expect even a lager yeast to throw flavors at 58F, it probably even been encouraged to munch on a little diacetyl. Then with cooling it back down to 50F, it might get a little sleepy, in which case you can just rouse it again with a swirl and/or temperature bump, or, it'll continue as planned. Good lesson learned, but my guess is no harm no foul.

 

[RM-MN]

When you took your hydrometer reading did you taste it for diacetal? I've seen several references to lagers that did not produce detectable amounts of diacetal which then makes a diacetal rest unnecessary.

 

[homebrewer_99]

I think it will be fine. If you did a 90 minute boil your chances of diacetyl generation is less than a 60 min boil.

In the past I've check my carboy and smelled butter. Most people just let it set at room temp for a few more days. Me? I just add a small sprinkling of Nottingham to the surface and wait 3 days...ALL signs of diacetyl GONE. It works every time.