r/Homebrewing • u/BlizardLizardWizard • May 14 '26
Help with low efficiency
Hi,
I've been brewing for a bunch of years now, but more recently started actually calculating out my efficiency for all grain brews. I've noticed that for the few I've done this for, my calculated efficiency has been unexpectedly low. I was hoping r/homebrewing might be able to help me figure out why.
As an example, my most recent recipe was a DIPA. I used 12lb pearl malt, 1lb wheat, 1lb, caramel 20L.
Mash water: 14lbs/grain x 1.4qt/lb = 4.9 gal
Water temp: 167F
I preheat my mashtun (large blue Igloo) with 175F water, which I then discard.
I add the 167F water to my mashtun and slowly stir in the grain.
Temp check reads 154F.
Steep 120 mins. Temp remains relatively stable, but at 85 mins, the temp dipped to 148, and I added 1/2 gal 175F water to bring it back up to 151F. Temp check at mashout was 149.5F.
I vorlauf and lauter, then fly sparge with 170F water to bring the pre-boil volume to 7 gal.
I measured a brix of 11.1 with a refractometer, which I converted to a gravity of 1.048.
Efficiency Calculation:
PPG = (Vpreboil x gravity points)/lbs grain = (7gal x 48)/14lbs = 24
Efficiency = PPG/PPGmax = 24/37.7 = 64%
I used table on typical malt yields in How to Brew to estimate the PPG max.
Wondering if it's the extra 1/2 gal used to temp adjust or if I'm not calculating the value correctly. Any input is appreciated.
9
u/dfitzger May 14 '26
Why are you mashing for 120 mins? Most conversion is happening in the first 15mins.
The extra 1/2 gallon in a 7 gallon batch will throw the numbers off for sure.