Not sure if I am doing this right or not. I brewed a batch of beer and checked for efficiency. Total grain bill was 9 ¼ pounds, Final wort volume was 6.625 gallons, & final OG was at 1.048. This was tested before the boil. My figures show I have about a 34 PPG. What would be the % of efficiency be?
This is Palmer's chapter on mash efficiency. This should answer your question. http://www.howtobrew.com/section2/chapter12-5.html
It depends of the type of malt you used. Homebrewers usually calculate efficiency based on a standard PPG per pound for each type of grain used. Without knowing the varieties you used, I'm guessing you got pretty good efficiency if you extracted 34 PPG.
Are you saying that the theoretical contribution of your grain bill was 34 PPG? Need to know the grain bill before you/we can calculate efficiency.
I had 8 pounds of german pilsen malt, 1 pound of munich malt, & 1/4 pound of wheat malt. total was 9.25 pounds. Not sure how to get the percentage out of all this. I guess I will read the section that scurvy311 provided above...
Okay, I'll make some assumptions about the potential PPGs of the grains... German Pils: 37 PPG Munich: 35 PPG Wheat Malt: 38 PPG Now, compute the total potential points from these grains and the amounts you used... Pils: 37 PPG x 8 lbs = 296 Points Munich: 35 PPG x 1 lb = 35 Points Wheat: 38 PPG x 0.25 lbs = 9.5 Points Add all the above to get 340.5 points. That's what you would get at 100% system efficiency. What did you actually get? Your OG was 1.048. So that's 6.625 gallons, at 48 points per gallon. Multiply... 6.625 Gallons x 48 Points per Gallon = 318 points extracted and successfully transferred to your kettle. So, out of 340.5 points possible, you got 318... 318 / 340.5 = 93% Efficiency. That's very, very high. (This was back of the envelope. Someone feel free to check the math.)
Thanks Vikeman, is there a chart somewhere that gives the ppg on the grains? Not sure where you got those figures. When I did my fly sparge it took me an hour. Maybe that helped get for efficiency...
I got them out of my head, so these may not match exactly, and it varies from maltster to maltster and from crop to crop. But here's one reference... http://www.beersmith.com/Grains/Grains/GrainList.htm
A lot of the on-line retailers supply this info. I usually look for it on their websites when I buy grains. You can also sometimes find it on the maltsters websites. But the approximations you find in software are pretty good. A good crush, a well-designed mash tun, and slow fly sparge all can contribute to high efficiency. I batch sparge and tend to be happy with efficiency in the 70-75% range. At the homebrew level, great efficiency is not paramount, but it does get you bragging rights in certain circles, like homebrew forums. If the 93% calculation is right, you have now earned the right to strut like a peacock.
In addition to my 'like' of pw's post I'll add that there is no 'correct' efficiency, just your efficiency. Unless it's super low, like 60%, why worry? I'm generally at 80-85% and am very happy with this. Most small commercial brewers are around 92-93% so you're in good company.
I also tried something different that might of contributed to this efficiency. A friend told me to do this. I set my mill down to about .50mm Lowest it goes. Next I laid my grains out on a cookie sheet and lightly misted them with water. I put them back in a bucket and stirred then let set about 10 minutes before crushing. It was a finer crush and the moisture did not break the hulls apart as much. It was a better-looking crush. I am thinking this might of helped.
It most certainly did, as long as you don't get a stuck mash (50% efficiency beats the hell out of a stuck mash, IMO).
