Hi all, first off I read the article below and calculating BH and Mash Eff seems simple enough, but I'm having an issue with Mash Eff.... http://beersmith.com/blog/2008/10/26/brewhouse-efficiency-for-all-grain-beer-brewing/ Stats: Potential = 1.098 (Malt Analysis Potential) SG = 1.057 (Into Kettle) SG = 1.074 (Into fermenter; OG) BH Eff. = 74/98 = ~75% (recognizable/normal number for this) All the above seems normal, now my issue: Mash Eff. = 57/98 = ~58% (Supposedly normal is 70-80%) Am I doing something wrong in my calcs here? Beersmith says my estimated mash eff is around 78%. If more information beyond this is needed please let me know and I'd be happy to provide - just wondering if I'm doing something very obviously wrong. Thank you!
The problem is you are not adjusting for volume. There's an inverse relationship between volume and gravity points. As you boil away water, the sugar/dextrin concentrations increase. For example... 57 points pre-boil, in 6.5 gallons. Boil off 1.5 gallons to get down to 5 gallons. 57 x (6.5/5) = 74 ETA: I don't know how you calculated your predicted gravity numbers, but also keep in mind that hops will absorb some wort (a wort loss) and that may (or may not) have been taken into consideration. Ditto for kettle dead space and transfer loss if applicable. Just depends on the assumptions behind the calculations. (These losses account for the difference between Mash Efficiency (a function of the sugars that make it out of the mash tun) and Brewhouse Efficiency (a function of the sugars that make it into the fermenter).) But your major concept here is still boil off.
^^^ I like this. In relation, efficiency is points received from a gain over sugar points possible in a grain . It's like how I had to figure out how I got a C in every math class I ever took. points received / points possible Preboil gravity will always be a little lower than post boil gravity. Let's assume you don't cheat by adding malt extract or water after the boil. If you ever got to taste maple sap from a tree and maple syrup in it's final form, it's the same concept. 20 gal of sap boils down into 1 gal of maple syrup. We ferment the boiled down version of what you get out of the grain. Water evaporates from the kettle. Sugar doesn't.
Fixed it - thank you both for your help! The following tool also helped me out - filling in the distinct volumes & gravities at each stage in this tool really helped me understand the big picture. http://www.brewersfriend.com/brewhouse-efficiency/
You may have transposed something, but Brewhouse Efficiency can't (by definition) be higher than Mash Efficiency. That's because you can't get more sugars/dextrins (from the mash) into the fermenter than you got into the kettle.
Interesting - I'll look into it further. I'm actually making a spreadsheet (I know you have an insane one VikeMan), I can send it to you if you're interested. Right now it only does the most basic calcs, so it's still pretty simple.
