I recently made a few equipment changes to my system and am having trouble with my mash efficiency. I know that there will be a period of instability until I brew more with the new equipment. I have brewed 2 batches so far and have had a very large variance in my mash efficiency…72% for the first, 66% for the second. I expected my numbers to be a little wonky for a while, but that’s a pretty big spread.
I switched my MLT from a 10 gallon Polarware and false bottom to a Blichmann 10 gallon Boilermaker with AutoSparge and false bottom. I used to get 75% consistently with my old system. Has anyone had similar drops/variances with that equipment?
The beers I brewed were an amber (72%) and a hefeweizen (66%).
If it isn’t the equipment change, where should I be looking in my process to get things more consistent?
If everything else in your process is the same but the equipment then that’s where the issue lies. IMO 2 batches of 2 completely different recipes is not enough to dial something in.
I would try and brew the same recipe a few times and see what you get. If the same recipe produces the same numbers each time then use that as your efficiency calculation moving forward
I have had efficiency reductions when using high percentage of wheat malt in my grist. A Hefe would display that. I expect that when you brew your next all barley beer, the efficiency will return. I don’t know why wheat does this, but I accommodate for the efficiency reduction in the recipe formulation.
Sounds mostly like the new equipment/ system to me, assuming you were consistent with the prior 75% efficiency. If you weren’t consistent in the 75% beforehand, I’d point at least partially to crush. I know because I’ve been there - I wanted to pull my hair out back in the 90s when I knew I had my process down to consistency, but didn’t have that in efficiency. It was the inconsistency in the crush I got from my LHBS that was the final variable. For a few years I got them to double crush my grain and got a bump up to ~ 80% and then finally broke down and bought a mill, where I could obviously mill to my satisfaction.
But, Martin is right in terms of efficiency with wheat - it goes down. No surprise with the efficiency loss there. Best to ‘build’ in a few points of loss in to your recipe. Good luck !
Even milling your own grain can result in variances, if your gap slips a bit. Just happened to me and it was the first thing I found. Like Martin says, also, wheat caused it for me previously on a 50% wheat grist, so adjust the bill accordingly…
Other than a reduction in dead space, I am curious as to why you moved from a 10-gallon Polar Ware kettle with a false bottom to a 10-gallon Blichmann kettle with a false bottom. I would never trade my 10-gallon 361BP for a 10-gallon Blichmann kettle. However, then again, I prefer to own kettles that have welded fittings.
Martin brings up a good point about the wheat in your recipe. Wheat kernals are usually smaller than barley kernals and often need to be crushed at a smaller mill setting. Rye malt is smaller still.
As was also mentioned, pH will definitely affect your efficiency. A good pH meter is a dandy brewing item to own. Essential? No. But certainly helpful.
I am in the same boat as the OP and it drives me crazy! I mill my own grains and I average 68% efficiency and normally get between 65-71%.
I am brewing right now and just took my preboil gravity. A whopping 59.8% efficiency! This did have a lot of wheat but I normaly get 70% for my normal wheat beer which has the same amount. I am hoping that my sample wasn’t sufficiently mixed so we will see what the post boil gravity is…
My process and equipment has not changed for quite some time. I was hoping that having my own grain mill would help me stabalize my efficiency but it has not.
When I brew the same recipe, my efficiency is the same so I guess that is good…
I have my kettle calibrated and use a tape measure to get my volumes. My preboil volume is always 6.23 gallons.
This recipe has a pound of rye. Similarly to thoughts about wheat, maybe the rye wasn’t milled properly which partially explains my lowest efficiency to date. If I do this one again, maybe I will use flaked rye to see if there is a substantial difference…
I don’t get lower efficiency with wheat. This could be because I might crush a bit finer than others. It could also be because I only use Great Western white wheat which has a grain size comparable to 2row.
I’m not sure how I do it, but I nail my Beersmith predicted OG 90% of the time. Crush grains myself. Never adjusted the gap. Mash pH of 5.2-5.6. Single batch sparge. Semi-accurate +/- 2* mash temps in a cooler. 45-60 minute mash.