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12/12/08 06:40 PM  
Negative effects of low mash temp
What happens if you mash around 130-139....does it just make for an extremely thin bodied and fermentable wort or might there be some other negative effects? Any thoughts? Couldn't find any info really about mashing at such a low temp....
12/12/08 07:01 PM  
Re: Negative effects of low mash temp
Longer time to convert so possibly less extract than a more typical mash temp if you mash for a standard amt of time. But most mash times are plenty long by a decent shot - this is what leads people to talkk about the 15 minutes mash.

Harder to drain the grain bed since the visosity is higher.

Differing mash temps favor different enzymes. 150ishF tends to balance the enzymes activity. Lower will favor one type over the other.

I seem to recall many yrs ago on the homebrewdigest, some data showing differing sugars resulting which is what gives the differing fermentability.Steve Alexander tended to be a name I recall from those types of discussions.

do a search over there. its a pretty good resource from the days before the BBB. Now it seems to have lost favor with forums.


12/12/08 09:29 PM  
Re: Negative effects of low mash temp
I should have said "assuming you get normal extract"....

So extract is fine in the end, with good sparge time, just got there with a super low mash temp.

"Differing mash temps favor different enzymes. 150ishF tends to balance the enzymes activity. Lower will favor one type over the other."

-So you think it would just be highly fermentable and thin bodied?

12/13/08 12:05 AM  
Re: Negative effects of low mash temp
I'd say more thin bodied than normal. Most of us are used to belgian mouthfeel so its usually not a problem unless its really alcohollic or you're looking for a big mouthfeel beer.

what type of beer are you referring to with a low mash temp?


12/13/08 05:46 AM  
Re: Negative effects of low mash temp
Ben, you don't mean 130-139 then mashing out do you? That would barely approaches a beta rest and is nowhere near an alpha rest. Actually your low end is in the protien rest range. But surely you know all this. Why would you feel a sub-beta mash schedule would produce a fermentable wort?
Seanywonton (Sean White)
12/13/08 10:36 AM  
Re: Negative effects of low mash temp
Take a look at this from How To Brew:


I think the main drawback from going that low is that malt starches do not gelatinize well at that temp. They don't fully gelatinize till you get up to around 149.

Plus if you are just looking for extra fermentability, you should be fine at 145 and I don't see any reason you would want to go lower.

But really the question should be, what is your ultimate goal in the beer?

12/13/08 11:44 AM  
Re: Negative effects of low mash temp
Well the beer in mind is a high-ish gravity wit bier.

There's no goal, say it happened by accident. It rested at that low a temp for an hour, then mash out/sparged with water at 170+.

So Steve, you think it would be hardly fermentable?

12/14/08 09:46 AM  
Re: Negative effects of low mash temp
Well, I have to say I have never done a mash routine anything like this, so to be objective I need to state I have no direct experience here. But the reason I've never done it is that its contrary to the theory of mashing as I understand it. When you say it was 130 - 139, if that was really closer to the low end then its possible - maybe likely - that neither of the enzymes necessary for conversion would have been activated. I think a lot depends on the specifics of your mash out. So you added 170+F water. What did that bring the mash to? Adding, say, 175F water to a 135F mash could not give you a mash out temp. The ultimate temp would have to be somewhere in between 135F and 175F. Exactly where and for how long seem like really important factors. After all, both alpha and beta-amylase are in between those temps.

Ben, I have also never done an iodine test this late in the game, but since its a really simple way to determine if you're starchy my guess is that it would still reveal the nature of your wort. I'd try one, see if you get ink or tang.

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