Sense Check - 70c Mash

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WonkyDonkey

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I'm hoping to get a brew on tomorrow that has a low(ish) target OG of 1041, 3.8% ABV.

After tinkering around in Brewfather I've gone for a mash temp of 70c for 90min in the hope that the beer will not dry out and finish around 1012. The grainbill includes a high amount of both flaked and malted oats, in the range of 25%.

Firstly, if I mash at 70c do I risk potentially not extracting all of the available sugars from the grain? Given the amount of oats, is there a risk of any off-flavours being produced further down the line at these temperatures?

I usually mash in the 65-68 range for a variety of styles, hence my hesitance when going out of my comfort zone 😬
 

peebee

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70C is fine. The enzymes "burn-out" a bit quicker (especially beta-amylase that breaks dextrins down to simple sugars) but they'll keep going long enough. I mash low-alcohol beers (<1%) at 74C, including high-ish proportions of oat malt (last brew had 16-17%).

I'll probably push mashing up to 75-76C next time because lack of attention caused my last low-alcohol beer to start mashing at 70C (it wasn't "low-alcohol" by the time it finished fermenting!).
 

WonkyDonkey

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70C is fine. The enzymes "burn-out" a bit quicker (especially beta-amylase that breaks dextrins down to simple sugars) but they'll keep going long enough. I mash low-alcohol beers (<1%) at 74C, including high-ish proportions of oat malt (last brew had 16-17%).

I'll probably push mashing up to 75-76C next time because lack of attention caused my last low-alcohol beer to start mashing at 70C (it wasn't "low-alcohol" by the time it finished fermenting!).
Thanks for the vote of confidence. Is a 90min mash about right or do you think that I'd get the same efficiency if I went shorter at 60min or 75min?
 

Hopsteep

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I’ve mashed at about 80 degrees before by mistake (dodgy thermometer) and whilst my efficiency was low the beer was fantastic- huge body and mouthfeel. 70-75 is a good range for English style beers where you want to add body and leave the FG a little high
 

peebee

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Thanks for the vote of confidence. Is a 90min mash about right or do you think that I'd get the same efficiency if I went shorter at 60min or 75min?
I only mash for 30 minutes, but what I'm doing is a bit "odd".

I'd say 60 minutes is quite long enough (some main core recipes will do this at 66-67C). It's bound to carry some "suck-it-and-see". There is (was?) a commercial UK beer mashed at 74C (don't remember its name now).
 

WonkyDonkey

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I only mash for 30 minutes, but what I'm doing is a bit "odd".

I'd say 60 minutes is quite long enough (some main core recipes will do this at 66-67C). It's bound to carry some "suck-it-and-see". There is (was?) a commercial UK beer mashed at 74C (don't remember its name now).
Thanks again, think I'll go at 70c and take readings from 45min onwards to see how conversion is going 🤞
 

Zephyr259

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60 mins at 70c should be fine, I've done similar mashes before when wanting a higher FG. The mash runs faster at hotter temps, I don't really ever go past an hour but if I did it would be when I'm down at 63-64c.

There's no reason your efficiency would suffer from a high mash as you'll still convert the available starch to sugars, there will just be a greater percentage of unfermentable sugars compared to a lower temperature mash.

What are you making?
 

WonkyDonkey

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60 mins at 70c should be fine, I've done similar mashes before when wanting a higher FG. The mash runs faster at hotter temps, I don't really ever go past an hour but if I did it would be when I'm down at 63-64c.

There's no reason your efficiency would suffer from a high mash as you'll still convert the available starch to sugars, there will just be a greater percentage of unfermentable sugars compared to a lower temperature mash.

What are you making?
Thanks. I'm brewing a clone of Sonoma by Track, GF's favourite session beer. I've brewed it once before, only my 2nd ever brew, and it came out really well but as I was in my brewing infancy I just let it ride and it finished low at 1007 on a 66c mash. A year on and with a few tweaks I'm hoping for an improvement on my first stab and more body to it 🤞
 

Zephyr259

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Thanks. I'm brewing a clone of Sonoma by Track, GF's favourite session beer. I've brewed it once before, only my 2nd ever brew, and it came out really well but as I was in my brewing infancy I just let it ride and it finished low at 1007 on a 66c mash. A year on and with a few tweaks I'm hoping for an improvement on my first stab and more body to it 🤞
Cool, I'm not familiar with that beer but sounds good. What yeast are you using?
 

WonkyDonkey

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Cool, I'm not familiar with that beer but sounds good. What yeast are you using?
For something that is 3.8% it drinks a lot bigger, highly recommend it.
This time I'm going with the Lallemand Verdant yeast, hoping to get some nice esters come through
 

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