85% partial mash efficiency???

So I just built the Rubbermaid cooler conversion MLT kit and brewed a partial mash of Fat Tire Amber Ale. 6 lbs grain, 1.6 gal water in the mash tun, of which 1 gallon drained off. Then I used about 2 more gallons to sparge. Eventually I ended up with 3.3 gal of pre-boil zwort, and a temp converted gravity of 1.055 (before adding the LME). According to brewersfriend.com, I got an efficiency around 84-85% from the grains.

Is that even possible? I've never gotten anywhere close to that before - although, my eventual OG was 1.060 instead of the expected 1.050 so something came in high.

bbriscoe said:

I got an efficiency around 84-85% from the grains.

Is that even possible?

Click to expand...

Start to question it when you get efficiencies of 97%!!! I have a reputation for achieving somewhat ridiculous efficiencies and have come to live with it. I attribute it mainly to my setup; rubbermaid coolers w/ false bottom and to the LHBS mill and my procedure. I would not worry about it too much and yes, it is possible! After achieving 90%+ efficiencies for some time, I decided to draustically increase my sparge time to 10min or less... This now gives me efficiencies in the range of 75-85% which is much more manageable and I feel less of a risk of tannin extraction from husks. This is a great place to start; speed up your sparge rate. Again, don't worry too much about it... try some more batches and see what efficiencies you get. So long as you know what to expect, you can adjust your grain bill accordingly.

Here is a link to a forum on the matter that I posted a while back:

https://www.homebrewtalk.com/f36/idea-lowering-efficiency-153808/

Hope this helps!