How to I check my efficiency?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Well-Known Member
Feb 28, 2009
Reaction score
I have been searching around and nothing I have found is really making this clear to me...

After soaking my grains and rinsing, can I use my hydrometer and if so, how do I determine the efficiency percentage?

Try to keep your answer simple, please..:)
most AG recipes are calculated at 75% efficiency. The recipe will have an estimated O.G. and a Estimated Pre Boil Gravity. When you take your reading you will subtract what you got from the Estimated Gravity and that is how many points you are off. for example if the recipe is 1.045 Estimated O.G. and you get 1.040 then you are 5 points shy and 70% Effciency. Remember if you have to either cool your pre boil sample or calculate the temp difference when you measure.
Hmmm. I don't have enough knowledge to even ask what I want to know....

If I'm doing just 3 or 4 pounds of grains, is there a way I can check the water/wort for sugar content and get a reading from that? Or is the only way to know what my efficiency is to know what something before I soak/rinse the grains? For instance, I have to know what my estimated Pre Boil Gravity is supposed to be....?

man this is confusing.
The simple answer is that you need to calculate 100% efficiency and then measure your wort and see what percentage of that you got.

You'll need a chart like this one that gives the potential for various grains.

From the chart; German Pils has a potential of 1.037 (also can be expressed as 37 pts/lb/gallon...that's points per pound per gallon). So if you mashed 1# of German Pils malt and yielded 1 gallon of final wort...the gravity would be 1.037 @ 100% efficiency. But you won't get'll get less...say you got 1.034. 34/37=92% so that's 92% efficiency.

If you mashed 1# and got 2 gallons of wort then you'd divide by in that case 100% efficiency would be 37/2=18.5 and your gravity @ 100% eff would be 1.0185. But you'd only get some fraction of that (your efficiency).

Ya know what...better to just read BobbyM's primer.:)
It's almost just as easy to make a simple Excel spreadsheet and use that. I made one in the late 90s and I keep improving it but it's still basically the same as it was then. My spreadsheet is more accurate for my brewing than the one @ Tasty Brew (I think some of these programs use the wrong extract potential numbers or something)...but I manually enter the extract potential numbers for each brew.