Author Topic: Mash temperature and final gravity  (Read 1234 times)

Offline trapae

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Mash temperature and final gravity
« on: December 21, 2014, 04:53:26 PM »
I've always wondered this but have not done the experiment to find out. I'm sure some of you have. I understand that mash temperature will select for non-fermentable versus more fermentable sugars. But will this actually affect final gravity points or just mouth feel? For instance if I brew the exact same recipe on the exact same equipment and mash one batch at 148deg and one batch at 158, will the final gravity points be significantly different?
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Offline denny

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Re: Mash temperature and final gravity
« Reply #1 on: December 21, 2014, 06:21:07 PM »
Mike Karnowski of Green Man in Ashville NChas recently posted some info about that, but I'll have to dog up his conclusions.  I recall that the two were unconnected, but I can't recall which was affected by mash temp.
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Offline HoosierBrew

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Re: Mash temperature and final gravity
« Reply #2 on: December 21, 2014, 07:20:29 PM »
I've always felt that mashing @ sub 150F I got lower FGs than above 150. I never experimented with the same grist just to test for that though.
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Offline denny

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Re: Mash temperature and final gravity
« Reply #3 on: December 21, 2014, 08:08:30 PM »
I sent Mike an email asking him to remind me where to find his results.  I'll let ya know what I hear.
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Offline trapae

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Re: Mash temperature and final gravity
« Reply #4 on: December 21, 2014, 10:19:38 PM »
Thanks Denny, conceptually I would think if there are more fermentable sugars around, more would be turned in the ETOH AND Co2 and the final gravity would be less but I don't know if it really works out that way.
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Offline majorvices

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Re: Mash temperature and final gravity
« Reply #5 on: December 21, 2014, 10:38:53 PM »
My experience is low temp equals lower fg.

Offline hopfenundmalz

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Re: Mash temperature and final gravity
« Reply #6 on: December 21, 2014, 10:44:15 PM »
I think it depends on the malt used and if it has a bunch of Alpha and Beta. The studies that Kai and Greg Doss did for Pils malt said 152-153F gave the best attenuation. There are data that say lower is better, maybe for Pale Ale Malt with is low in Alpha. For "hot" US malts with high Alpha and Beta, it might be around 158F, but that is speculation on my part.

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Offline klickitat jim

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Re: Mash temperature and final gravity
« Reply #7 on: December 22, 2014, 01:23:26 AM »
My answer is Yes there will be a difference,  No it will not be significant. At least not with most modern malts. But I suppose it depends on what significant means. For example if 158 gets you to 1.012, 148 might make the exact same grain bill go to 1.010.

Offline Stevie

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Re: Mash temperature and final gravity
« Reply #8 on: December 22, 2014, 01:29:00 AM »
I have recipe that fermented from 1.039 to 1.003 at 148° and to 1.006 at 158°. That's semi-significant, but only one set of data points.

Offline a10t2

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Re: Mash temperature and final gravity
« Reply #9 on: December 22, 2014, 02:43:45 AM »
There are data that say lower is better, maybe for Pale Ale Malt with is low in Alpha. For "hot" US malts with high Alpha and Beta, it might be around 158F, but that is speculation on my part.

I think this is pretty much accurate. I accidentally mashed my APA grist at 77°C and it still attenuated 74% ADF. The norm (at 67°C) is 80%.
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Offline hopfenundmalz

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Re: Mash temperature and final gravity
« Reply #10 on: December 22, 2014, 03:06:55 AM »
There are data that say lower is better, maybe for Pale Ale Malt with is low in Alpha. For "hot" US malts with high Alpha and Beta, it might be around 158F, but that is speculation on my part.

I think this is pretty much accurate. I accidentally mashed my APA grist at 77°C and it still attenuated 74% ADF. The norm (at 67°C) is 80%.
A little over 170F? Wow!
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Offline denny

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Re: Mash temperature and final gravity
« Reply #11 on: December 22, 2014, 04:33:07 PM »
Here's the reply I got from Mike.  The book he mentions is "Homebrewing: Beyond the Basics".

It's in my book, we also did a blind triangle tasting at the brewery when one of our beers finished at 1.020 instead of the usual 1.010 and nobody could pick it out. My theory is that long chain sugars from mashing high aren't perceived as being sweet (just taste some malto dextrin powder) or contributing body. On the other hand, residual simple sugars from an incomplete fermentation will taste cloyingly sweet.
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Offline trapae

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Re: Mash temperature and final gravity
« Reply #12 on: December 22, 2014, 04:59:44 PM »
Cool, interesting.  Love this forum.
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Offline jtoots

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Re: Mash temperature and final gravity
« Reply #13 on: December 22, 2014, 06:32:35 PM »
It's in my book, we also did a blind triangle tasting at the brewery when one of our beers finished at 1.020 instead of the usual 1.010 and nobody could pick it out.

very interesting

Offline denny

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Re: Mash temperature and final gravity
« Reply #14 on: December 22, 2014, 09:58:44 PM »
It's in my book, we also did a blind triangle tasting at the brewery when one of our beers finished at 1.020 instead of the usual 1.010 and nobody could pick it out.

very interesting

Just to clarify that quote, it's in Mike's book, not mine.
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