I have a decision to make: I brewed a an imperial porter with an og of 1.087 and used wyeast 1318. As of Friday (2 weeks into fermentation), it was down to 1.029. I had been fermenting in a chest freezer at about 63F inside the freezer, not the actual wort/beer. In order to let it fully attenuate, I brought the freezer temp. up to 72F. I checked it yesterday, about 36 hour later and it was down to 1.026. Its clearly not done fermenting. The decision I need to make is this: I am leaving Wednesday for a 3-week work trip, thinking this beer would be ready to keg either today or tomorrow. Do I hurry up and do a 24-hour cold crash and keg tomorrow night, before my trip and leave it at 40F to mature during those 3 weeks or let it sit at 65F for the 3 weeks and let it fully attenuate, if it hasn't already? Will the three weeks on the yeast do harm?
My guess is that for an Imperial Porter you would not notice any ill effects if you let the beer sit on the yeast for a total of 5 weeks (2 weeks which have already transpired plus the additional three weeks). If this was my situation I would let it ride for 5 weeks in the primary. Cheers!
Given the choice between 3 more weeks on the yeast or packaging a possibly not fully attenuated beer, I'd choose the former. What FG were you expecting (and why)?
Target was down around 1.024, so I am not far off. I would be fine with 1.026, but I always like a few days of yeast "clean up" after full attenuation. I just want to make sure its done attenuation more than anything though. @VikeMan
I would definitely let it ride for the 3 weeks you'll be away if you're not sure the yeast are finished and have cleaned up. The risk for autolysis in 3 weeks seems relatively low and I would not expect any ill effect. A Russian imperial stout that I brewed this past winter sat in the primary for almost 5 weeks and it received scores in the mid 40s at a recent competition. The risk I see in kegging the beer before you leave is that if the yeast have not finished then it's possible for diacetyl that is not currently detectable to show up in the taste an aroma while it it cold conditioning and you're away.
