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General Category => General Homebrew Discussion => Topic started by: jschoell on November 28, 2010, 05:40:15 AM

Title: low mash temp
Post by: jschoell on November 28, 2010, 05:40:15 AM
I undershot my single infusion mash temp... I wanted 150 but got 145. I mashed for 1 hr. How will this affect the final product?
Grain bill:
12 lb belgian pilsner
8 oz victory
8 oz aciduated
1 lb corn sugar for 30 min
1 hr boil

Hop schedule:
2 oz amarillo fwh
1/2 oz amarillo 30 min
1 oz cascade 30 min
1 oz cascade 3 min

irish moss 15 min

WL cal ale yeast 1L slurry

thanks!
Title: Re: low mash temp
Post by: tygo on November 28, 2010, 01:24:05 PM
You're going to have a beer with a lower final gravity.  I'm guessing between the low mash temp and that pound of corn sugar in there you'll see something around 90% apparent attenuation. 
Title: Re: low mash temp
Post by: kerneldustjacket on November 28, 2010, 02:25:57 PM
jschoel...can you give a few more details?
What starting gravity were you shooting for?
Did you measure your starting gravity, and if so what was it?
What batch size where you shooting for? 5 gallons? 5.5 gallons? What did you actually get for a starting volume?

Your beer should attenuate more than you expected, but if your gravity is high enough, that won't necessarily be a bad thing.
Title: Re: low mash temp
Post by: bluesman on November 28, 2010, 02:52:15 PM
I'm assuming you achieved conversion...what was your OG? How did you measure the mash temp...did you take multiple readings in random areas around the mash? As was said, mashing lower will yield a more attenuative wort. The beer will have a lighter body with a higher ABV than it would if mashed at a higher temp.
Title: Re: low mash temp
Post by: Kaiser on November 29, 2010, 01:24:59 AM
Missing the mash temp by that much and ending up in the mid 140s is not that big of a deal. Just change your mash schedule on the fly. Simply go from a single temperature mash to a two step saccharification mash (also called Hochkurz mash)  by mashing at 145F for 30 min, for example, and then raise the mash temp to 160 and hold it there for another 30 min. This temp raise can be done with an infusion of boiling water or a decoction.

Do you know the efficiency that you got from your mash?

Kai
Title: Re: low mash temp
Post by: jschoell on November 29, 2010, 04:36:20 AM
jschoel...can you give a few more details?
What starting gravity were you shooting for?
Did you measure your starting gravity, and if so what was it?
What batch size where you shooting for? 5 gallons? 5.5 gallons? What did you actually get for a starting volume?

Your beer should attenuate more than you expected, but if your gravity is high enough, that won't necessarily be a bad thing.

OG was 1.065 and I collected about 5.5 gallons from a 6.5 gallon boil. I'm wondering if mashing low like this has any effect on the head retention and flavor.
Title: Re: low mash temp
Post by: jschoell on November 29, 2010, 04:41:41 AM
Missing the mash temp by that much and ending up in the mid 140s is not that big of a deal. Just change your mash schedule on the fly. Simply go from a single temperature mash to a two step saccharification mash (also called Hochkurz mash)  by mashing at 145F for 30 min, for example, and then raise the mash temp to 160 and hold it there for another 30 min. This temp raise can be done with an infusion of boiling water or a decoction.

Do you know the efficiency that you got from your mash?

Kai

I think it is around 70%. Does adding boiling water destroy some of the enzymes that are needed to convert the sugar? Will this lower my attenuation?
Title: Re: low mash temp
Post by: Kaiser on November 29, 2010, 05:59:11 AM

I think it is around 70%. Does adding boiling water destroy some of the enzymes that are needed to convert the sugar? Will this lower my attenuation?

How does this efficiency compare to previous batches?

The addition of boiling water will denature some enzymes, and that's intended. But it is not so much the boiling water that is doing that but the rise of the mash temp in general. Once you have created most of your fermentables at 145 F the mash temp is rised to largely destroy the b-amylase and supercharge the a-amylase. The latter will convert starches that have not been converted up to this this point. The longer you let the mash sit at the 145 F rest (generally called the Maltose rest) the more fermentable the resulting wort will be. I find that 30 min works great to create worts with an average fermentabiliy of ~80%.

Kai
Title: Re: low mash temp
Post by: denny on November 29, 2010, 04:27:48 PM
Does adding boiling water destroy some of the enzymes that are needed to convert the sugar?

Not unless you add so much that you hit a really high overall temp.  Whenever I do a multiple infusion mash, I always use boilong water.  as long as your mash temp remains within standard parameters, it doesn't affect attenuation.