understanding efficiency

Hey guys-
I've been all-grain brewing pretty successfully for about a year, but haven't ever really paid attention to efficiency. I would like to dial down my system and start understanding these details better. Could anyone help me? I want to know how to hit my target OG better. The other day I missed my target high by like 15 points. Is there any way to adjust your efficiency while sparging? I know there is such a thing as pre-boil gravity. Can someone help me make sense of all of this?
Thanks!!!

I brew in a 5 gal round cooler with a false bottom and fly sparge.

I suggest reading this....http://howtobrew.com/section2/chapter12-5.html

And also, thumb through the rest of the section on all-grain. I doubt anyone can explain it better than Palmer.

Ah well this could lend to a lengthy discussion. I suggest you do some reading. This is a good place to start.

That being said, efficiency is calculated by determining how many fermentable sugars could be contributed at 100% and then dividing your actual sugar extraction by the 100% efficiency sugar extraction.

As for how to improve your system, well, grain crush is where you should start. After that you may consider mashing at a higher water/grain ratio, stirring the mash more, lautering more slowly, switching to fly sparging or batch sparge in two batches instead of one, adopt a recirculating mash, better temperature management, etc.

efficiency is a product of SG and quantity of collected wort. you need to figure out what the theoretical maximum yield is for the grain you using. take the max SG and multiply by the amount of water used in your brew. do the same with the collected wort. wort gravity multiplied by the amount of wort collected. now divide the wort number by the theoretical number and multiply by 100.

Example:
max OG = 1.085
measured OG = 1.073

gallons of water in = 7 gallons
gallons of wort out = 6.25 gallons

max ppg = 85 * 7 = 595
real ppg = 73 * 6.25 = 456.25

% efficiency = 456.25/595 * 100 = 76.7%

typically people take an average efficiency for their system and use that when calculating their grain bill.

pre-boil gravity is, like the name implies, is the gravity of the wort before you boil it. during the boil you will of course lose water to evaporation. this concentrates the wort raising it's SG. the pre-boil gravity is what you use when calculating your IBUs for a batch.

Buy designing Great Beers by Ray Daniels, and read chapter 5

-a.

ajf said:

Buy designing Great Beers by Ray Daniels, and read chapter 5

-a.

Click to expand...

Excellent book.