Stupid mash temperature mistake - results?

[Canucklehead_Chicago]

Okay, through a series of totally stupid things (which I am too embarrassed to mention), I ended up with an initial mash temperature of 164F on a 5-gal ESB batch. Target was 152F.

I immediately added 2 quarts of cold water, and got the temp down to 160F (I know, should have added ice...). Desperate now, I pulled the bag out of my 10 gal cooler mash tun and let it sit for 20 minutes dangling over the cooler. I "fluffed" it a bit to try and get some heat exchange. After the 20 minute pause, I put the bag back in the liquid, gave everything a good stir and the temp came back at 150F.

I then let the mash continue, adding a further 15 minutes to the 60 min total time that the grain was in the liquid (not counting the 20 min pause). I checked the mash conversion with iodine, and after 75 min there was no black.

Drained the tun into my kettle and proceeded to the boil. Post boil gravity was 1.055 while target was 1.054. So I figured I was close enough to the mark despite the problems.

Not I'm 5 days into fermentation and it's stuck at 1.032 (temp 68F). I had done a 1 liter starter with Wyeast 1968 for 36 hours, so I believe that I pitched enough yeast. Last night a added an 11 g pouch of Safale US-05 and raised the temp to 70F. As of midday today - nothing - no fermentation, no activity. I tasted the beer and while it's sweet, I'm not getting any other off flavors.

So - just let it ferment for another 10-14 days in primary (just in case) and then keg it? If it carbs up okay, I guess it will make a decent session ale (at 3%).

Thanks.

 

[beernutz]

What oxygenation procedure did you follow?

If you in fact mashed at too high and ended up with excessive unfermentables I don't believe there's much you can do about it except live and learn.

You've already pitched additional yeast and bumped the temp slightly but the new yeast will have to deal with both alcohol and insufficient oxygen so prognosis is not good. Your plan to give it more time then keg seems sound.

 

[Canucklehead_Chicago]

I used an oxygen stone with a good flow for 1 minute prior to pitching the primary yeast.

 

[Frilock]

Well you could always brew up a mini batch (gallon or so) and add it in to your main batch if you have the space in your fermenter for it. Won't help the sugars the yeast can't use in the first batch, but it'll might bring the overall FG down. Otherwise I would say let it go. You might really like it.

 

[doug293cz]

You could try adding amylase enzyme to the fermenter. This will break down some of the unfermentable sugars into fermentable ones. Amylase works slow at fermentation temps, but it does work. The problem to watch out for is that it might work too well, and make the wort too fermentable. If you are kegging, you can cold crash to stop the fermentation at a reasonable FG, but if bottling, fermentation will restart during conditioning, and you could end up with bottle bombs. So, if bottling, you would have to let it ferment to completion, even if it gets too low.

Brew on

 

[The_Bishop]

What are you checking your final gravity with?

 

[Tommydee]

I did this with a hefe, one of my first BIAB, hit about 162. I use oxygen stone, had a juicy yeast starter with wyeast, and it stalled at 1.021. Didn't mix before taking temp, and must have overheated strike water. Sucks because was brewing the hefe for friends, not a big fan...in the end, it had all the flavors, but no alcohol and sweet. Since I wasn't willing to give it to friends, dumped it after a gallon or so to free up the keg. Only beer I've sewered to date.

Mash temp matters.

 

[Canucklehead_Chicago]

After some research, I decided to give amylase enzyme a shot. I figured at such a high mash temp that I denatured the enzymes and ended up with a lot of unfermentable sugars (based partly on the fact that the iodine test detected no starches). I threw a teaspoon of of the powder into the carboy on Monday night, raised the temp to 72F and gave the fermenter a (gentle) swirl. After about 36 hours, the SG started to drop from the 1.030 it was stuck at. It's now Thursday afternoon, and it's at 1.019, so an 11 point drop. I'm in no rush to keg, so I'm going to give it another week to work its magic. At least the ABV is now 4.7 instead of 3.3, and probably not as sweet.

 

[doug293cz]

Sounds like things are progressing nicely.

Brew on