65% attenuation after 11 days- time to panic?

[Dan_K]

Hey guys,
I brewed my first BIAB batch (Imperial Stout) and the beer did not attenuate. It stalled at 1.050.

I brewed the same beer (slightly modified recipe) and my gravity readings were 1.036 after 5 days, 1.034 after 11 days. This is only 65% attenuation and the yeast is supposed to be good for an average of 75%. I am using White Labs WLP007 Dry English Ale yeast and I pitched a 2L starter from a stir plate. I also dosed the 1.103 wort with some yeast nutrient that the local HBS store carries.

Fermentation quickly rose to nearly 80 degrees after 24 hours but I was able to cool it down and it came down to 66 degrees after ~8 hours. After 5 days I moved it to a slightly warmer part of my house and it's been sitting between 64-66 degrees since then.

Anyway, I really need it to come down 5-10 more points.
I could pitch some more yeast such as WLP099, add some yeast nutrient, add some Amylase enzyme. Then only thing I can't really do is make it warmer, I would love to hold it about 70-72 degrees but it might be too late regardless. I'm just worried the longer I wait the less chance I have of saving this beer.

Additional Info:
I have been mashing in my boil kettle but it seems like the temperature drops off quite rapidly without any sort of insulation. I ended up doing a direct-fire to bring the mash temp up. And again to bring it up to 170 for mashout. My kettle has a very thick bottom and even with my burner on full blast it hasn't scorched anything or damaged my bag.

I also did a starch conversion test, twice, but I feel like the results were inconclusive. I think I might need to watch a youtube video. Also, my efficiency sucks.

 

[Dan_K]

Gonna try putting it in the bathroom with a spaceheater and getting it up to 75 deg or so.

 

[dmtaylor]

Just swirl, swirl, swirl. If I recall correctly, WLP007 is an extremely flocculant yeast. If the yeast all settles out too fast, then it's not in good contact with the beer and thus your fermentation can stall. So just swirl the fermenter a couple times per day, and then after a couple more days of that, see if the gravity begins to fall again.

Heat could also help, but I think swirling might help even more. Or just do both.

Good luck!

P.S. Patience is also a requirement with really big beers like this one. Patience! It's going to get done on its own schedule, not a human's schedule. Patience.

 

[Brew_G]

Firstly, a 2L starter is fairly decent under pitch for a big beer like this (assuming a 5-gallon batch). It could be that the yeast crapped out due to stress if it really was under pitched.

Did you aerate/oxygenate?

What was your mash temp? What was the target? What was the temp as the flame was on it?

 

[Mer-man]

Hydrometer or refractometer reading on that FG?

 

[Dan_K]

Hydrometer or refractometer reading on that FG?

Hydrometer reading.

Last night I added a 1/2 dose of Amylase enzyme and used my sanitized super-long carboy spoon to gently agitate the yeast layer on the bottom.

This yeast is really crazy- I first noticed this when I made my yeast starter. It forms a super-dense layer of yeast, almost like pudding. When I swirled the starter, it stays in clumps (looked like rotten milk, kind of). Apparently that's normal for WLP007 because it's "super flocculating".

Today I am going to move it to a small room and run a space heater to bring it up to ~70 deg F

 

[dmtaylor]

Last night I added a 1/2 dose of Amylase enzyme...

NOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!! Crap, I should have warned you. Ugh. Well, hope that works out for you. If bottling, don't bottle for a good 2-3 months. Otherwise, KABOOM. If kegging, you might be alright. Just hope you like a really bone dry beer.

 

[Dan_K]

Somehow I posted this twice. I will monitor the fermentation, but I doubt 1/4 tsp of Amylase is going to dry out my beer that much.

I will have to do some more reading. From what I've seen so far it generally works for a week or two.

 

[Dan_K]

NOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!! Crap, I should have warned you. Ugh. Well, hope that works out for you. If bottling, don't bottle for a good 2-3 months. Otherwise, KABOOM. If kegging, you might be alright. Just hope you like a really bone dry beer.

You were right after all.

I bottled this beer at 1.032.

I just pulled a bottle after 60 days in the bottle, it's SUPER carbonated and tested at 1.026. No bottle bombs yet, but I lose almost half of the volume to foam eruption when I open it.

 

[dmtaylor]

Well.... It's often most helpful to learn the hard way. That's the best way I know that I've learned. It's impossible to know who we can and cannot trust on the interwebs.

Pour each bottle into a pitcher 15 minutes before you're ready to drink it. Then enjoy. Cheers.

 

[SlitheryDee]

This might be a good candidate for offgassing no? Like, refrigerate all the bottles for a couple of days to maximize absorption and then uncap/recap all of them to get rid of the excess co2. I dunno how that will work if they all erupt when you uncap them though. In any case, having highly pressurized bottles around would make me nervous.

 

[dmtaylor]

I kind of agree. At least keep them all cold and contained in a sturdy case. And pray they don't KABOOM.