System efficiency calculations

[Bourbonbeard]

As the title suggest I'm currently trying to calculate our cooker efficiency to better help us with fermentation. I have the fine extract numbers from our grain supplier and have our normal brix readings from our mashes. We add enzymes to our cook to help with the conversion for both Liquefaction and Saccharification and use a jacketed corn cooker to mash everything in. Each time I run the numbers to find our efficiency through a calculator (specifically the Chase The Craft one because its uses extract potential), I seem to be getting numbers over 100% efficiency. Our gravity before pitching is 1.0875 and the grain extract percentage is 81.8%. We do a 1800 gallon total mash with 4000# of grain. Any help of where I'm going wrong on calculations would be appreciated

[Tom Lenerz]

Not sure if this answers your question, but what is your goal with this number? Are you trying to calculate mash efficiency or overall process efficiency? Is this a theoretical exercise or are you using it to make decisions? How many PGs are you getting from distillation, what about PGs of hearts?

To be honest, the only number that really matters from a business perspective is PGs/LAA per bushel/pound/whatever unit. I do everything in PGs per bushel, it is quick, easy, and relevant -- I buy bushels and I sell PGs. This month I am averaging 4.8 PGs per bushel for my high-rye bourbon. I once heard ethanol plants average the equivalent of 5.3, so that is my target ceiling, and I know from history I can get as low as 4.5 with my rye whiskies. If something is outside that scope I know something is wrong. 

[SlickFloss]

Per usual I agree with Tom (please take note everyone who insists Im a curmudgeonly F _ _ _ that agrees with no one and smells his own farts). From a process standpoint we look at pgs/bushel for efficiency when looking back at our runs. We're running 36% rye bbn right now and consistently hitting on average 5.2 pgs/bushel. From our standpoint when that number is off we look to yield in PGS, if we didn't pul about 990-1010 PGS off our 5.5k gallon ferment we know there is a yield issue. Looking back on the run itself if we saw really wild vent fluctuations and cooling surges and inconsistent sump temps with consistent steam input and mash feed we know it was a distillation issue: we lost that ethanol because we didn't operate well. If we don't see those things but then go back to whats in the beer well lets say we see it didn't finish in line with where it should it was super low in PH and left 3 or 4 brix on the table: well hey it was a fermentation issue. If it finished out but you have a bunch of dough balls in your beer well or fermenter with raw centers or it did finish out but doesn't pass a starch test: it was a cooking based issue.

 

If you track your input in, your process of cooking, your brix and ph through fermentation, and your yield you can diagnose where in the chain you're having issues.