Questions regarding primary fermentation...

...well, it's not exactly about primary fermentation, but that's where I am in the process, so let's start there!

I'm in the process of brewing an extract Dead Guy Ale clone from AHBS. I made a really boneheaded sanitation error when fermentation blew the lid off my bucket (put the lid back on the bucket, with full krauesin layer reaching the top of the bucket, without sanitizing the lid). Despite that, I think I lucked out, because I tasted the brew today while taking a hydrometer reading, and it tastes really good. It's actually amazingly close to Dead Guy now, which really surprised me considering how young the beer is.

Anyway, onto my question. The original SG of the brew was supposed to be around 1.064, which I hit on the head. So, I decided to do primary in the basement, because I had a sneaking suspicion that fermentation may be a bit more explosive this time around (I finally made an accurate prediction with my homebrewing :rockin: ) The only problem with this is that I live in Wisconsin, and this time of year temperature swings are pretty extreme from day to night. It's not uncommon at all to be in the mid 50's during the day, and mid 20's at night. Despite that, there's one room in my basement that seems to maintain a somewhat constant temp. of around 60 degrees.

I had read Rogue's brewmaster saying he brews with Pacman yeast at 60 degrees, but I went ahead and threw a brew belt on my primary anyway, because, I knew it would reduce lag time. So, during initial fermentation, up until the point the lid blew off the bucket, the wort was at a consistent 72 degrees. A day after the lid incident, the wort shot up to 77 degrees, which was more than I was willing to go, so I took the belt off, figuring fermentation would still take place, albeit a bit more slowly, at the cooler temperature.

Well fast forward two days to today, and I noticed that airlock activity is nonexistent. I decided to take a hydrometer reading ( I usually just rack to secondary when the airlock activity slows like this, but being a bigger beer, I wanted to see how far along I really was). I got a reading of 1.020, and the target final gravity is 1.014. Now, I'm not too far off, and maybe fermentation will complete to 1.014 in secondary, but I'm sort of thinking that fermentation has stopped. There's nothing going on by way of airlock bubbles at all. I wonder if yanking the brewbelt off midway through fermentation, and a rapid drop in beer temp somehow put the yeast to "sleep" (for lack of a better word)? Should I try swirling the bucket a bit? The other thing I was considering was just racking to secondary, and maybe bringing the temp up to the 70 degree range to see if things pick up again.

Then again, probably just racking it and leaving it in the 60 degree room is probably the most sensible thing. Even if the gravity won't go below 1.020, it still tastes pretty damned good, by my judgement. What do you all think?

There's a lot of variables there, but a couple things. I don't know the attenuation expected out of the yeast, you're already at 69% most yeast attenuate into the upper 60s into mid 70s, (there are some higher and lower). The type of extract, some are more fermentable than others. Time, you'll probably drop a few more points. And temp changes, you're right the yeast may have been shocked and slowed down some. The biggest one, the warm temperatures probably had those yeast working overtime and the ferment is mainly complete.

uwmgdman said:

There's a lot of variables there, but a couple things. I don't know the attenuation expected out of the yeast, you're already at 69% most yeast attenuate into the upper 60s into mid 70s, (there are some higher and lower). The type of extract, some are more fermentable than others. Time, you'll probably drop a few more points. And temp changes, you're right the yeast may have been shocked and slowed down some. The biggest one, the warm temperatures probably had those yeast working overtime and the ferment is mainly complete.

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That's what I was generally thinking as well. BTW, I am using Rogue Pacman yeast, and the apparent attenuation is pretty high, like 80% or more, I believe.

I assume you do a lot of shopping at the Wine and Hop Shop? I was in Madison about a month ago and picked up one of their extract kits (Sven's Oatmeal Stout). It's been bottle conditioning for a week now, and I don't see any signs of carbonation yet, namely the yeast bed at the bottom of the bottles. My first two batches produced a sediment layer very quickly (within 3-4 days I think). Again, maybe the cooler temperatures are slowing things down a bit.

greg75 said:

That's what I was generally thinking as well. BTW, I am using Rogue Pacman yeast, and the apparent attenuation is pretty high, like 80% or more, I believe.

I assume you do a lot of shopping at the Wine and Hop Shop? I was in Madison about a month ago and picked up one of their extract kits (Sven's Oatmeal Stout). It's been bottle conditioning for a week now, and I don't see any signs of carbonation yet, namely the yeast bed at the bottom of the bottles. My first two batches produced a sediment layer very quickly (within 3-4 days I think). Again, maybe the cooler temperatures are slowing things down a bit.

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Yeah I get almost everything there. Everything is always fresh and they're always really helpful. The prices aren't bad either. About the bottles that are conditioning, it could be temps or yeast strain. Any highly flocculating yeast for me always takes at least a week to see much.....and even then I usually don't get too much sediment in the bottles. I'm sure the carbonation will come along fine, let me know how that oatmeal stout is from there, I might have to try it.