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Old 05-26-2012, 04:48 PM   #1
Jun 2009
Whetsone AZ
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Thing about doing a Decoction for a Hefe 5 gal batch,single Decoction Mash
how much of the grain shoud I do it to.

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Old 05-26-2012, 05:12 PM   #2
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Feb 2009
Tucson, AZ
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If you want to read about it check this link:

Otherwise, watch these three videos by Kai Troester he gives a detailed process of how to perform a decoction mash.

Here is another fun one to watch on how the guys from Brewing TV go about their decoction mash:

These are some pretty good videos that go over the process.

I hope this helps.

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Old 05-26-2012, 05:18 PM   #3
Nov 2004
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The nominal amount is 1/3 of the mash. In reality a bit more, like 35-40%, tends to work better as far as hitting temperatures. Use the total weight of the mash to figure your decoction pull, that is the combined weight of the grain and the water. For example, if you mash in with 10 lbs of grain and 10 qts of water you have a total mash weight of about 30 lbs which would give you an 11-12 lb decoction pull.

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Old 05-29-2012, 03:44 AM   #4
Jan 2011
Ferndale, WA
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Michael Dawson does it on that BTV episode. He mentions being taught the decoction mash by a decoction guru who always uses the following rule. One quart of thick mash for every pound of grain in the grain bill. 13lb grain bill, 13 quarts of thick mash should go into the decoction.

I've never done it, but I plan to do so in the near future. When I do go for it, I'll be using that rule of thumb.


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Old 05-29-2012, 11:40 AM   #5
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Jun 2006
UP of Michigan, Winter Texan
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Generally, you need to pull as much thick mash as you need to hit the next rest temperature. Brewing software (or great math skills!) is extremely helpful for this.

If you pull too much, you can overshoot your temperature when you put it back in the mash. If you don't pull enough, you can miss your temperature also.

I don't think I've EVER done a 13 quart decoction, though! That's a lot.

Normally, if I'm doing a protein rest, I'll do it on the high end (like 131 degrees) and then almost immediately pull the first decoction as I don't want to stay long at protein rest temps (I use well-modified malt). Then I hit the first saccrification rest, stay there for a time (30 mins), pull the next decoction for the second saccrification rest, and for the last decoction I pull thin wort instead of a thick mash for the decoction to mash out.

Normally, the amounts are 5-8 quarts or less, in a 5 gallon batch.
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