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Author Topic: How low can you mash?  (Read 7602 times)

Offline gmac

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How low can you mash?
« on: March 24, 2014, 12:56:21 pm »
On a recent Brewing Network show, Annie Johnson was profiled and she made a comment about making good light lagers and commented about mashing at lower temps for longer times, I think her comment was something about 138 for 2 hours.  Is this real?  Not sure how low you can go for fermentability. 
Has anyone down to these low temperatures for longer mash times in order to get better light lagers?
Thanks

Offline morticaixavier

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Re: How low can you mash?
« Reply #1 on: March 24, 2014, 01:07:59 pm »


according to this at that temp you would still have plenty of beta activity but would be slightly below gelatinazation temps  for most grains, if you do a decoction or a cereal mash that might not matter though.
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Offline kramerog

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Re: How low can you mash?
« Reply #2 on: March 24, 2014, 01:15:23 pm »
Limit dextrinase is active at that temperature (breaks down the 1-6 bond that the amylases don't touch) so the temp might produce a super low FG.  Presumably beta-amylase is also active, but slower than normal.  However, the low end of gelatinization temperature range for malt is ~140 deg. F so I'd assume that you can't go much below ~140 deg. F without loosing a lot of efficiency.

Was she talking about single infusion?

Anyway I was thinking of doing a low temp mash for a saison as a a possible way to speed up fermentation with DuPont yeast so I'm interested in the forum's comments.

Offline Jimmy K

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Re: How low can you mash?
« Reply #3 on: March 24, 2014, 01:16:05 pm »
Remember too that those are peak enzyme activity ranges - the edges are not hard edges as depicted on most graphs, but very fuzzy. All of those enzymes are somewhat active (though very little) at any temperature. Conversion at 138F may be much slower, hence the 2 hour mash.
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Offline mabrungard

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Re: How low can you mash?
« Reply #4 on: March 24, 2014, 01:42:48 pm »
Yes, as Jimmy points out, the enzymatic activity is affected by temperature and a longer mash time would be appropriate for a lower temperature mash. 

I do have to wonder about the effect of mashing at such a low temperature though. That would be taking a lot of body and head potential out of the wort. While I am a proponent of mashing to get fairly high fermentability, I'm concerned that this approach might be too much. Conversely, too many brewers mash at too high a temperature and the fermentability suffers and body is excessive.

I'm curious why she prefers to mash this low? I prefer the low end of the alpha amylase activity.
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Offline HoosierBrew

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Re: How low can you mash?
« Reply #5 on: March 24, 2014, 01:55:49 pm »
You learn something every day - I've never heard of anyone mashing that low. I've mashed pretty low (146-147F) for Saison, but, wow -138?  Clearly she has had success with light lagers, or otherwise you'd have to question the need (and end results) of going that low.
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Offline hopfenundmalz

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Re: How low can you mash?
« Reply #6 on: March 24, 2014, 02:08:54 pm »
Michael Lewis talks of an hour at 140F for hot American malts,followed by a rest at  158F or a little higher.
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Offline gmac

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Re: How low can you mash?
« Reply #7 on: March 24, 2014, 02:14:07 pm »
I may have heard it wrong but I'm sure someone else would have listened to the show too and can back up my story.  I do realize that things will move slow at that temp and thus the 2 hr mash. I am a bit confused too because she talks about Denny's batch sparging being one of the best things she does and also talks about decoctions at another point and I don't know how compatable those two methods are (I know that they can be compatible but it seems like unnecessary work).  I'm still planning on doing a saison soon when my back feels a bit better so I'm considering a 2-hr 142 degree single infusion mash to bring on more fermentability

Offline denny

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Re: How low can you mash?
« Reply #8 on: March 24, 2014, 02:15:53 pm »
I am a bit confused too because she talks about Denny's batch sparging being one of the best things she does and also talks about decoctions at another point and I don't know how compatable those two methods are (I know that they can be compatible but it seems like unnecessary work).

So right, yet so wrong...;)  Sure you can do decoctions while you batch sparge.  I've done it too many times.  I agree about it being unnecessary work.
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Offline kramerog

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Re: How low can you mash?
« Reply #9 on: March 24, 2014, 04:11:31 pm »
Here is the link: http://s125483039.onlinehome.us/archive/ses_2014-03-10_anniejohnson.mp3

At ~1:45 into the show, she says that light lagers need to be mashed at 138 F for about 2 hours.  She is also talking about the capabilities of a picobrew brewing system in terms of holding really long mash temperatures and doing multiple steps; she works for picobrew.   I don't know enough about light lagers to know why she is mashing at 138 F.

Offline Jimmy K

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Re: How low can you mash?
« Reply #10 on: March 24, 2014, 05:44:37 pm »
Maybe she goes for super high attenuation so she can use less adjuncts and get the same light body with a little more flavor.

Maybe. I'm making things up here.

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Offline klickitat jim

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Re: How low can you mash?
« Reply #11 on: March 24, 2014, 08:40:17 pm »
Maybe if you're using less modified malt too?

Offline dkfick

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Re: How low can you mash?
« Reply #12 on: March 25, 2014, 06:14:01 am »
She is talking about making water... I mean American Light Lager.... so shooting for a very light body.
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Offline reverseapachemaster

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Re: How low can you mash?
« Reply #13 on: March 25, 2014, 08:07:36 am »
I seem to recall reading that budweiser is mashed at 142F for two hours so that would seem to support her argument.
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Offline Stevie

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Re: How low can you mash?
« Reply #14 on: March 25, 2014, 08:14:34 am »

I seem to recall reading that budweiser is mashed at 142F for two hours so that would seem to support her argument.

2 hours? I'm surprised they haven't found a way to mash in 5 minutes.