Another mashing problem, Temp this time

Hey guys so if you read my last post about the false bottom tube failing, then you know I'm not on any kind of a roll when I tell you that two of the three thermometers I had were failing during trying to keep the temp at 152. It was soo bad that it told me it was at 131 at times and so I added some 195 degree water to compensate but didnt know it wasnt working. So when I finally realized something was the matter with the thermometer it was like 40 mins into the mash process. I got my other thermometer and tested it and the mash was like 179!!! So it had been this way for like 30-40 mins! So I cooled it down to 151 with cool water. Then this thermometer after 15 mins said the temp was like 131, I knew this was false so I mixed around the mash to make sure there were no hot spots. This didn't help, and as soon as I took this thermometer out it read 212F. I was like SH$#!!! TWO IN A ROW, THIS CANT BE HAPPENING!!! So I got old trusty out, which didn't have a long cord to put into the mash so I had to just gauge from the top of it what the real temp was, slightly cooler I suppose. I did mash out around 171 though. Now here is my question: Will having it at 179 for 40 mins really do anything that bad? I got the starting SG right on the money when I was done, So is it gana throw my flavors way off or anything else? I know I read something about it in the home brewing book by Palmer but I just can't find the book for the life of me.

Temperatures that high probably extracted tannins, this could cause the beer to taste astringent. Chances are that the hot water killed most of the enzymes and there won't be a good starch conversion, so you won't extract lots of sugar from the grains. Basically, the beer might not be amazing, but you never know, it might work out in you favor.

psi3000 said:

Now here is my question: Will having it at 179 for 40 mins really do anything that bad? I got the starting SG right on the money when I was done, So is it gana throw my flavors way off or anything else?

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Geez, sorry to hear about your bad luck. Hope it doesn't discourage you from tackling the next batch -- each of these little mishaps is a learning experience and quite common. The next batches will go much more smoothly, I am sure!

Regarding your question, I suspect that you won't detect any astringency from tannin extraction -- the temps weren't really hot, and the pH of your mash would have been low enough to prevent any significant amount of tannin extraction.

However, I bet you had a low efficiency, right? And mashing at that temp is probably going to lead to low attenuation on your ferment on top of that. This occurs because those high mash temps would have probably denatured your beta amylase enzymes, which are responsible for converting starches to maltose (the highly fermentable sugars). Your alpha amylase enzymes may have survived, but they would have produced larger, less fermentable sugars. The end result will be a thin and sweet beer, unfortunately. But it still might be quite drinkable, especially if you can blend it with another beer to balance.

Let us know how it turns out. And best of luck on the next one!

I can't speak from experience on this one as I've never had this issue, but I would tend to agree with the post above. This probably is not going to be the best batch of beer that you've ever made but the only way that you're going to find out is to bottle/keg it and give it a try.

Thanks for the info guys. Flyguy you said "going to lead to low attenuation on your ferment." If by this you mean its not going to ferment as well, I have to say it is bubbling away. Maybe it will stop to soon though. And the target in the recipe said I should have a starting gravity of 1.063, which I was dead on. So I don't know, what do you think, could this still be a bad sign?

Very strange, are you sure you can trust any of your thermometers?

psi3000 said:

Thanks for the info guys. Flyguy you said "going to lead to low attenuation on your ferment." If by this you mean its not going to ferment as well, I have to say it is bubbling away. Maybe it will stop to soon though. And the target in the recipe said I should have a starting gravity of 1.063, which I was dead on. So I don't know, what do you think, could this still be a bad sign?

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Well if you hit your target SG, maybe it wasn't as hot as you thought? If it wasn't, then it is going to taste pretty darn good, I bet!

And yes, regardless of what happened, I am not surprised that it started fermenting well. The question is whether it will finish well. Actually, make sure you get a good FG reading -- that will be pretty diagnostic. Let us know what happens.

Oh, one other thing -- search for some posts on thermometer calibration. There is lots of useful information here on how to use things like ice water and boiling water/boiling alcohol to test the accuracy of your thermometers.