Help! Mash too hot, have I ruined it?

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nigelnorris

nigelnorris

Beavis at Bat
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Heater malfunction led me to add the grain to water that was well into the 80sC.

I spotted it straight away, added cold water to try to bring it down, but not enough room. So I baled a load out than added more water. Took about ten minutes of baling and adding before I got it down to proper temperature.

Is 5 or ten minutes of that kind of heat going to have seriously harmed it? I'd hate to spend months of fermenting, lagering, etc only to find that it was ruined from the off.

It's early enough so that if I chuck it now then all it's cost me is 5kg of grain, I've got plenty more of that so I can get another brew on today and still have the hops all ready to go.

What is the collective opinion?
 
Most of the conversion is done in the first 15 minutes (if memory serves me correctly) so I guess it'll depend on how much over temp you were and for how long. You'll probably end up with a lot of unfermentable sugars id have thought. Normally I'd say not to worry about it but it sounds like you're brewing a lager which I'd expect to be light and clean which I'm not convinced you'll get with the high initial temp especially if it was high for 10 minutes. Also, when you were bailing some of the hot wort you could have lost some sugars so may end up with a lower og.

Normally I'd say don't worry about it, hops and malt flavours can mask a lot of errors but with a lager I'd probably start again.
 
Decided to keep it. I can't detect any real unpleasantness like excess tannin or whatever else might have gone wrong. I have a sweet tooth anyway and the beers I enjoy most are the ones that come out a bit sweet so I'll cross fingers and hope that it turns out to be one of those accidents that ends up with a positive side. I kept the stuff that I baled out, used it for sparging.
 
Do you know if the temp was still in the 80s for long. Today, due to the cold weather I got my water to 75c before adding the grain. Once i had stirred in all the grain it was 65c
 
Leon103 said:
Do you know if the temp was still in the 80s for long. Today, due to the cold weather I got my water to 75c before adding the grain. Once i had stirred in all the grain it was 65c
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Yes, it was in the 80s after I'd added the grain, must have started high 80s. Took me 5 or 10 mins to get it down into the low 70s.

Or at least I think so, been having trouble with my inkbird all day so there's a bunch of guesswork in there. All my own fault, dropped the probe into the water and for some reason it just stuck at about 65C and kept heating way beyond that. After the horse had bolted I took it out and gave it a good clean and it's been ok since then.
 
I think you will probably have a wort which has a lot of unfermentable sugars in it. This will lead to a high finishing gravity and low ABV.

It is worth fermenting and you can then make a decision about whether to chuck it or not if you end up with a 2% beer.

You might be lucky and enough of the beta-amylase might have survived to do the job.

I don't know if this is an option, but I would look for a yeast which is highly attenuative to help do the job and maybe ferment at the warmer end of the lager temp range to help the yeast. Saflager w-34/70 can get over 83% attenuation so might be a good choice.
 
There will be some unfermentable sugars in it making it a little sweeter than you wanted unless you counteracted this with more hops than originally planned.
 
If it finishes fermenting at too high an FG, indicating lots of unfermentable sugars, could you not add some amylase enzyme?
 
Simonh82 said:
I think you will probably have a wort which has a lot of unfermentable sugars in it. This will lead to a high finishing gravity and low ABV.

It is worth fermenting and you can then make a decision about whether to chuck it or not if you end up with a 2% beer.

You might be lucky and enough of the beta-amylase might have survived to do the job.
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OG is 1050 which should give me >5% without the cockup. If it goes as low as 2-3% it will probably be undrinkably sweet. We'll see.

Simonh82 said:
I don't know if this is an option, but I would look for a yeast which is highly attenuative to help do the job and maybe ferment at the warmer end of the lager temp range to help the yeast. Saflager w-34/70 can get over 83% attenuation so might be a good choice.
Click to expand...
Already started ir with saflager 23, and I'm keen to test my new cooler box so I'm sticking to 12C for now. I'm hoping that an extended diacetyl rest should help it finish off as much as possible. I'll stick a hydrometer into it after 10 days and see where it's at.
 
If you do end up with 'unfermentable' sugars in your wort, lager malts can ferment the unfermentable sugars that ale malts can't, that's why they're drier in general (is is maltriose? I dont quite remember), so hopefully you'll end up with at least something drinkable but not quite as dry as it would be otherwise
 
If it comes out too sweet you could always boil up some hops in water to add extra bittering to counter the sweetness, its what I've done before with a sweet brew to good effect.
 
nigelnorris said:
OG is 1050 which should give me >5% without the cockup. If it goes as low as 2-3% it will probably be undrinkably sweet. We'll see.
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If it does finish with a high gravity it is unlikely to be very sweet. The dextrins which are created at high mash temperatures are called sugars (because technically they aren't starch) but they are not very sweet at all.

Fingers crossed that the yeast does it's stuff and there was enough enzymic activity left when you got the temperature down. The fact you got a wort with 1.050 OG suggests that the enzymes were certainly working to extract the sugars during the mash.

Let us know how it turns out.
 
Rule Number One of Home-Brewing is "Don't Worry!"

At worst it will finish up cleaning out your drains ... :thumb:

... and at best it will be an unrepeatable superb brew that you wish to share with your friends! :thumb:

Personally, I don't like really bitter beers so I always mash on the high side (i.e. above 60 degrees celsius) and I have to look back over 40 years to remember a brew that finished up cleaning out my drains! :thumb:

However, a Barley Wine currently conditioning for nearly eight months is coming very close to finishing up down the drain; but then again, it may yet become an adjunct to turn a Pale Ale into a Mild Ale by adding some of it to the boil for that extra bit of "chocolate and colour"! :whistle: :whistle:

I love this hobby! :thumb: :thumb: :thumb:
 
For anyone who might come across this with the same or a similar problem: Nothing to worry about, fermented out at target 1010 and no odd tastes or blemishes that I can detect.
 
However my problem now is that the weather has warmed up and I have no way to lager it so it won't come out quite right anyway.

I have storage down to about 10C, think I might try dry hopping it. The boil hop was Hallertau plus I have Summit, Cascade, Chinook, Simcoe and Amarillo aplenty.
 
I've only done one AG so far, a pale ale from the have a go at AG "how to" on here. I didnt know a high mash temp caused unfermentable sugars and mashed at 70°. I fermented it and it wouldnt go below a FG of 1020 so I chucked it. I would recommend you decide whether to keep it at the end of fermenting depending on your FG.
 
Ale said:
I've only done one AG so far, a pale ale from the have a go at AG "how to" on here. I didnt know a high mash temp caused unfermentable sugars and mashed at 70°. I fermented it and it wouldnt go below a FG of 1020 so I chucked it. I would recommend you decide whether to keep it at the end of fermenting depending on your FG.
Click to expand...

I think you might have missed a post, look two up and you'll see that it went very well and finished as expected :)

Tbh I can't imagine how a 70C mash would cause your brew to finish so high, don't think a degree or two either side would make so much difference.
 
This bloke reckons that there's zero discernable difference in the final product when changing between 64C and 72C mashes

http://brulosophy.com/2015/10/12/the-mash-high-vs-low-temperature-exbeeriment-results/

Ok there's a gazillion variables that will affect it and you could probably choose the right ingredients, water quality, and yeast strain and show the opposite to be true, but I'm still not convinced that 70C would [on its own] cause 1020 FG.
 

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