Efficiency

[Jake]

I was pretty bummed after one of my last batches when I hit approximately 62% efficiency for my IPA. I did a bit of reading and made a couple changes for my last batch, and saw a dramatic improvement. Thought I'd share.

Just 2 things I did differently. I read that the width of the grainmill should be approximately the thickness of a credit card. Pretty general statement, but I only slightly tightened it for that my credit card fit snugly, because I found it was sliding in there pretty loosely (please refrain from any "that's what she said" jokes) when I did the ole credit card in the grainmill test ... Second, I tried starting with the water in the mashtun, and added the grain to the water. I went 3 degrees above the suggested strike water temp, and I hit my mash temp of 153 bang on; I tried this just one other time and came in 3 or 4 degrees below my anticipated 152, so this was just to make up for it. I'm assuming that if you actually took the time to heat up the mash tun with some boiling water, you wouldn't need to do this, but I'd rather just heat the strike water to a few degrees more.

I entered the info into brewmate expecting around 70% efficiency (based on my dismal efficiency the prior batch), but ended up hitting closer to 85%, which I've never ever done. Not sure if this was just a fluke or if just slightly tightening the mill and adding grain to water really helped. Either way, pretty pumped about the result. Unfortunately cannot do another batch until the weekend, but I'll try again and see if I can get similar results.

[DandyMason]

Ill have to check my grain mill to see what I have it set to. Im usually around 70%... But I had better efficiency the couple times I sparged twice.

[Jake]

This was 19 pounds of grain for a 10 gallon batch, also, so not sure if that played a part. I'm going to try 15 or 16 pounds in a 5 gallon batch, and see what I hit for efficiency. Richard has a theory that the more grain you use, the lower the efficiency, so this may somewhat test this. He thinks that lighter beers get higher efficiency, but I'm hoping not because I'm not a huge fan of the lighter stuff.

[DandyMason]

Yeah I have definitely heard its tougher getting good efficiency with the 10 gallon batches, so 85% sounds, to me, pretty awesome. I am definitely going to make sure I am getting a fine crush with my mill. I have damn hard time getting anything above 70% with 5 gal batches.

[Richard]

9.5lbs/5 gallons is round about the range I would expect to see 80-85%, in addition to what I've experienced, the logic I was going off was: with all other things equal, higher grain bills equate to lower quantities of sparge-water per-lb to obtain the same boil volume. The main way to balance that, I figure, is to start with a larger boil volume and boil down.

e.g. (1.25 water:grain ratio, 0.125 absorbtion, want 7 gallons/28 quarts at the start of the boil)
10lbs grain = 12.5 quarts mash, losing 5 quarts to absorbtion, need 21.5 quarts sparge for 28 quarts.
20lbs grain = 25 quarts mash, losing 10 quarts to absorbtion, need 13 quarts sparge for 28 quarts.

Getting off-topic a little bit, I'm beginning to wonder if at the lower end it wouldn't be better to only sparge some ratio of the initial grain, to avoid tannin extraction. Anyone seen any numbers for a maximum ratio of sparge water to original grain weight when batch sparging?