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Old 10-18-2010, 09:13 PM   #1
Jun 2010
State College, PA
Posts: 22

Quick question regarding mash efficiency.

I have now done several all grain batches. I use a 5 gallon rubbermaid drink cooler with a false bottom. My first couple batches gave me an efficiency of about 74%.

However, as I have continued to progress I have started to treat my water to try and achieve a water profile closer to the source region of the style I am making. Since starting to treat my water I now consistently get an efficiency of 90 - 91%. This has been the case for several single infusion mashes and even a decoction mash.

I don't want to look a gift horse in the mouth as this certainly lowers my grain bill. However, based on the books I have read discussing the mash process, this is an efficiency that seem to be much higher than I should expect.

Is this anything I should be concerned about? Is it a possible indication of something wrong in the process, say milling the grains to fine?

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Old 10-18-2010, 10:49 PM   #2
Apr 2009
Richmond, VA
Posts: 691
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The books only say that because your average beginner home brew setup will often achieve something in the 70s. I use the same mash tun and I've always gotten relatively good efficiency. 100 percent efficiency would be ideal, but not really possible with the tools we have available as home brewers.

A finer grind will usually help efficiency to a certain extent. Not suggesting that you have done this, but it's easy to misread the hydrometer when you first begin. If your beers seem to finish higher in gravity than you're expecting it could be that you're misreading. This might not be the case, but I'm just throwing out ideas. Either way higher eff. is something to be happy about hehe.

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Old 10-18-2010, 10:56 PM   #3
Feb 2010
Cincinnati, Ohio
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The only concern you need have is jealousy from other brewers.

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Old 10-18-2010, 10:57 PM   #4
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May 2006
Lapeer, Michigan
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I have read that you do not want to be that efficient in the lauter 90's. I am not sure what book I read it in but they were talking about extracting to many tannings and other things you do not want in your beer.
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Old 10-18-2010, 11:21 PM   #5
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Aug 2009
Seattle, WA
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Originally Posted by Brew-boy View Post
I have read that you do not want to be that efficient in the lauter 90's. I am not sure what book I read it in but they were talking about extracting to many tannings and other things you do not want in your beer.

I intentionally lowered my efficiency to reduce tannin extraction. What I heard is that, ideally, you don't want to drain wort from the mash tun with gravity lower than 1.015. I'm not sure if this only make sense for fly sparging, which is what I do.
I used to drain wort as low as 1.010, now changed to 1.020 and have noticed a clear improvement in the quality of my beers.
Basically, you spend 1 or 2 extra pounds of base malt to get a better beer.
My current brew house efficiency runs around 70%.

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Old 10-18-2010, 11:44 PM   #6
Sep 2007
Boulder, CO
Posts: 132
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I hit a mid 90s efficiency when making a hefe this summer, coupled with the yeast nutrient I gave it, we ended up with ~7.5% alcohol beer. Drinking that while brewing in the heat got us toasted pretty quickly. The best thing is to know what your efficiency is and plan accordingly.
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Old 10-19-2010, 02:05 AM   #7
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Oct 2005
Long Island
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I don't think there could be any problems with getting a high mash efficiency (which you calculate by taking the gravity of the first runnings), but there definitely can be problems with getting a high mash/lauter efficiency. I can get very high efficiency if I over sparge, but the results are not pleasant. Like nilo, I am a fly sparger, and have intentionally lowered the efficiency that I could get in order to produce better tasting beers. Nowadays I get about 75% brewhouse efficiency, but today, I had a near stuck sparge. It took over 2 1/2 hours to sparge for a 5 gallon brew, and I ended up with 87% efficiency after adding about 1 gallon water to reach my required pre-boil volume.

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Old 10-19-2010, 02:22 AM   #8
Aug 2009
Charlottesville, VA
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I remember hearing on The Brewing Network an episode in which Tasty said he had to go and buy his own mill because his homebrew shop changed their mill settings and his efficiency jumped from 70% to over 80%. He said he didn't like the mouthfeel from his beers when brewed with higher efficiency.

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Old 10-19-2010, 12:09 PM   #9
Jun 2010
State College, PA
Posts: 22

Thanks everybody.

To answer some of the questions posed: it is my total efficiency that I am talking about - mass and lauter.

Also, I do think that my last couple of beers have had little to no mouth feel. Whereas previously that wasn't an issue. I will attempt to lower my efficiency for a brew and see what happens.

What is the best way to go about doing that? Should I just add the proper proportion of extra grains to the malt bill and stop sparging sooner? Then top the brew kettle off with water?

Is there a way to calculate how much additional grains I want to add? Say I wanted to stop sparging with a runoff gravity at 1.020. Is there a way I can calculate how many additional grains to add in such that I can have a runoff of 1.020 when I hit 6.5 gallons in the brew pot.

I'm not sure I phrased that last question very well, so I'll give it another try. Currently I hit my target gravities almost exactly when I calculate my malt bill at 90% and sparge until the runoff is 1.010. \Is there a way to calculate my grain bill so that I can be relatively confident that when I hit a runoff of 1.020 I will have my target gravity units in the brew pot?

If anyone could point me in the right direction on this I wold appreciate it.

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Old 10-19-2010, 12:25 PM   #10
Jun 2010
State College, PA
Posts: 22

Is it possible that the issue is mostly caused by my grain crush?

I live in Central Pennsylvania and do not have access to a LHBS. Thus, I need to order all of my supplies online. I currently do not have a grain mill so I have the supplier mill the grains for me. When I first started brewing I order from Since he was located in Ohio, which is relatively close and his extract kits were pretty good. However, shortly after progressing to all grain, I started to find that he oftentimes did not have the hops that I wanted. Due to this, I start ordering my supplies from Midwest Supplies as they are normally very well stocked.

Looking back through my brew notes, it was when I made this switch in suppliers (and hence milling) that I noticed the jump in efficiency from 74% to 90%. I had originally assumed that this jump was due to having treated my water which I also started to do at the same time. Perhaps that was a poor assumption on my part.

Has anybody else here used Midwest Supplies and noticed an issue with how they mill the grains?

Is it possible that the original milling is fine, but because the grains have to get shipped so far to get to me that they are pulverized by the shipping process when they reach me?

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