I’ve been doing all-grain for a while, and still have no clue how to compute brewhouse efficiency. Basically, I have my recipes in BeerSmith. I figure out my efficiency by tweaking the efficiency number in BeerSmith until it predicts the recipie will yield the OG I actually measured. I’ve seen online calculators that essentially do the same thing. Seems like cheating.

So what’s the by-the-book method for computing brewhouse efficiency?

That’s the best way to do it. The other little secret I can tell you for brewing new recipes is that gravity points plus brewhouse efficiency is usually almost constant. For example, say your average gravity on an average brew is 1.060, and your average efficiency is 75%. Your constant then is 60 + 75 = 135. So if you make a new recipe with an expected gravity of say 1.072, you know in advance that your efficiency might fall to 135 - 72 = 63%. And the reverse is true for smaller gravity beers, so a 1.050 beer might give you 85% efficiency. It’s not exact, but it will steer you into the right ballpark anyway.

Ahhh, yes. I seem to recall reading you posting about that “little secret” before, but it didn’t make sense to me when I saw it before, It’s starting to click in place now. I’ll have to go back and check my notes, but I think it will account for the variances I’m seeing.

You see, my wife likes more session-type beers, and we’re always a bit high when we brew for her. I prefer stronger fare, and we seem to always fall a bit short when we brew for me. Given that we do the same thing, regardless of who’s brew is being made; I’ve been wondering why we can’t get consistent efficiency numbers. We’ve both been a bit disappointed in the apparent inconsistency.