Trying to calculate my mash efficiency for a hefeweizen extract recipe. Reading “Designing Great Beers” and using it’s table to calculate. Ray Daniels has liquid extract potential as 1.037-1.039. Wouldn’t this drastically change with different LME’s? I used a wheat LME that’s 65% wheat extract and 35% barley LME (pilsner I think?). Also steeped 1lb. Munich. Here’s my calculations:
1lb Munich=1.035=35GU
6.5lbs. LME=1.038=(38x6.5)=247GU
Total=(247+35)=282GU potential gravity of grains
My OG was 1.059 at 5.5 gallons. So 59x5.5=325 total gravity of wort
With this I end up with (325/282)=1.15 or 115% efficiency which is obviously incorrect. Can anyone tell me where I went wrong?
Usually with extract batches if you have abnormally high or abnormally low gravities it’s due to incomplete mixing of the concentrated wort into the chilled water.
The gravity contributions will change with manufacturer and type, but not that significantly.
You’re right on with the brewing and measuring, just not the calculations. I put 6.5 lbs LME + 1lb munich into my brewing software and got a predicted OG of 1.062. 6.5lbs LME alone gives a predicted OG of 1.057. You’re right in the middle.
Unless you really love doing the calculations by hand, I’d recommend using brewing software. I like Beersmith which is under $30. I also used to use www.beertools.com where you can get a free account with slightly limited, but still useful, functionality.
This is actually something I was about to ask… probably close enough to not be its own thread.
So a lot of recipe analyzers (e.g. BeerTools) ask for your mash efficiency to calculate tons more data. As a partial mash & extract brewer, how does one accurately figure that out?
If, for example, I mash some amount of 2-row and crystal malts for 30 minutes, but am not very confident the temperature was accurate for what I wanted (too hot, too slow, etc), what should I do? This particular recipe was 4lbs grain, 3.2lbs LME.
BeerTools sets a default for partial mash recipes at 70%, and for someone still fighting a stovetop burner to get things right, how should I adjust?
You efficiency for any extract and sugar should be 100%. It is automatically set to that in BeerSmith, regardless of the manual setting. That should be the case for any brewing software.
Take gravity and volume readings after the mash/sparge, but before adding any extract or additional water. That’s all you need to calculate efficiency. You can do a weighted average of the grist to get a more accurate answer, but assuming the mash is mostly base malt this will be pretty close:
Eff = 1000V(SG - 1)/(36*W)
Where V is the wort volume in gal and W is the grist weight in lb.