# 92% conversion efficiency?!?

Discussion in 'Calculator Support Forum' started by BeerisYummy, Dec 3, 2020.

1. ### [email protected] New Member

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#1
I just ran this calculation again because I couldn't believe it. The BF efficiency calculator told me I got 32.6 PPG and 92% extraction efficiency. I entered all the malts, which consisted of 10 lbs Viking Pale, 2 lbs Canada Malting Malted Oats, and a smattering of other things, 14.5 lbs total. I entered the total water used as 5.5 gal. for the mash (BIAB) and 2 for the dunk-sparge, total of 7.5 gal. Pre-boil gravity, prior to top-up, was 1.063, temperature-corrected.
Is such a thing even possible? Where could I have made a mistake?

2. ### Donoroto Well-Known Member

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#2
Is it possible? Yes, of course.

Just a napkin calculation of efficiency of 14 pounds yielding 1.063 pre-boil says efficiency is very high, 90% being a reasonable number. So I don't see an error here. But I can understand the disbelief, I'd feel the same.

That said, if there was an error it could be in several places: The 1.063 reading itself, the grain types (Canada oats versus another brand) or amounts entered in the calculator, or less likely you used less water than you thought.

3. ### Nosybear Well-Known Member

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#3
Amateur! I hit 102% the other day.

92% is not far out for conversion efficiency (my 102% is - I suspect a measurement error in weighing out the grains). If part of that smattering was sugar and you added it to the mash tun, that throws the efficiency calculations for a loop. Bottom line, it doesn't look that unusual, maybe a touch high.

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4. ### Pricelessbrewing QA Software Tester Staff Member

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#4
88-94% is a reasonable average for conversion efficiency, 102 is definitely a measurement issue at some point.

It's worth noting as well that the correct conversion efficiency is calculated in the brew sessions "mash complete" brew log entry, however the "brewhouse efficiency" calculator has an incorrect formula right now. We're working on an update to get them aligned.

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