Author Topic: Brewhouse Efficiency and Grain Bill Size  (Read 401 times)

Offline mister2

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Brewhouse Efficiency and Grain Bill Size
« on: January 14, 2020, 09:30:28 AM »
I have an equipment profile for 14.5 gallon batches that I have used many times to successfully predict and hit post mash gravity.  The total grain for that size batch typically runs around 33 pounds.  The Brewhouse Efficiency set in the profile is 73%.  However, when I brewed a barleywine using that profile and same batch size, the resulting brewhouse efficiency was much lower at 56%.  Total grain was 77 pounds.  I have repeated these results twice, so I can rule out being a fluke.  My question is if BHE is related to total grain?  Should I maintain a separate equipment profile for beers having big grain bills versus one for 'normal' beers?  There have been no other changes equipment- or process-wise that should affect efficiency (grain crush, mash temp, etc.).

Offline Oginme

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Re: Brewhouse Efficiency and Grain Bill Size
« Reply #1 on: January 14, 2020, 10:24:26 AM »
Your mash efficiency can be directly tied to the size of your grain bill.  Since you have used this profile successfully in the past, I am assuming that there are no changes in the downstream process losses, which would then indicate that the loss is coming from the mash tun.  There is a limit to how much starch (and then converted to sugar) can be solubilized in the mash liquor.  Kai Troister has an excellent treatise on efficiency which can explain it much better (and in many more words) than I can right here.  The link is http://braukaiser.com/wiki/index.php/Understanding_Efficiency

I typically have had two equipment profiles for my system which split the range of gravity at around 1.080 to accommodate the difference in mash/lauter efficiency with the higher grain bills.  I later switched my high gravity brews to include a sparge step (my standard is full volume BIAB) in order to compensate and keep my efficiency in the same range for both higher and lower gravity recipes.
Recycle your grains, feed them to a goat!

Offline mister2

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Re: Brewhouse Efficiency and Grain Bill Size
« Reply #2 on: January 14, 2020, 01:03:11 PM »
Thanks so much for the thoughtful response.  I certainly didn't want to update my equipment profile to match the big beer recipe at the expense of messing up the numbers for 'normal' brews.  In the meantime I will continue to brew both high and low gravity beers and note the differences.  Cheers!

Offline BOB357

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Re: Brewhouse Efficiency and Grain Bill Size
« Reply #3 on: January 14, 2020, 04:26:27 PM »
You don't need to change your existing equipment profile. Just create a new one for the big beers or change the BH Efficiency on the design page for individual recipes. Neither will alter your normal profile.
Bob