High Efficiency Bad, Low Efficiency Good!?

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dmtaylor's picture
High Efficiency Bad, Low Efficiency Good!?

So I have this idea for a flavor / beer quality experiment that involves playing with high and low efficiency. You know how "they" always say that "no-sparge brewing results in superior malty flavors" or something to that effect. I do believe this is true, but I still need to run more experiments, eventually, to confirm it. Meanwhile, I have concerns that high efficiency results in the opposite: low malty flavors, even to the point of tasting watered down.

The low efficiency test subject is best produced through no-sparge. The high end test subject likewise ain't no problem if you crush like mad -- I got 95% brewhouse efficiency on my last batch without even trying. Granted, it was only a 2-gallon batch, so I sparge more so that I can boil off more water in my standard size kettle, i.e., smaller batches lead to higher efficiency, but anyway...

I have experienced this phenomenon in at least one previous batch where I got 94% efficiency -- it was an award winning Vienna lager, but with the judges all commenting, "tastes wonderful, no flaws, except that it seems kind of watered down", and I agreed, making the same comment even before entering any competitions. We'll find out in a few more weeks when this next current batch of 95% is finished. I'm serious when I say it was on accident. I was only shooting for low 80s.

This whole topic is perhaps best introduced through reference of a good long thread from a couple of years back on the BN forum. There were heated discussions on two sides, both promising to perform experiments, but then the whole idea just kind of died for whatever reason. Maybe we can pick up again where we left off. See here:



Hmmm, I've pondered over this

Hmmm, I've pondered over this and have so far decided that high efficiency is not a problem. As my efficiency got better and better (now averaging 95%) I was concerned about loss of flavor. My thinking goes like this. I use malt for two things, food for the yeast and flavoring in the final beer. This seems more apparent in extract with steeping grain brew where the extract is there mostly as yeast food and the specialty grains are primarily added for flavor, and not yeast food. My concern is that using less base grain (to keep the ABV in line) also means you are putting less potential flavor into the beer. I have not really found this to be the case, but for the record I do brew a lot of pilsners and other lagers, so that might make a difference.

Of course, an obvious correction for this is to add a bit extra of any specialty grains (for this purpose I would also extend this to Vienna and Munich malts, even though they are technically base malts).

I think there could easily be differences, but on the other hand I think they can easily be compensated for by changes in the recipe, so it seems a bit of a moot arguement. Another factor which may or may not be a concern, is that with more malt (to deal with lower efficiency) you have a lot more husk material, which might help with the sparge, but also gives you more opportunity for tannin extraction.

It seems a bit of pick your poison, and then take steps to counteract it. Each has their benefits and faults so just pick the one that you can more readily compensate for

denny's picture
I'm on the side that says

I'm on the side that says high efficiency isn't a problem, but I have never done a real test or tastings on it. I think this could be a great experimental topic.

Life begins at 60....1.060, that is!

One question then, along the

One question then, along the lines of my conversion versus flavor extraction idea. Obviously the easiest way to affect efficiency would be to change the crush. The question then is does the efficiency of flavor extraction parallel that of starch conversion or is it totally independent? If it does parrallel, then that would suggest efficiency might be a moot point - with respect to flavor.

I wonder if one could asses this simply by tasting the wort produced by mashing two different crushes. It gets a little complicated as some folks do get full conversion, and others might not, and that could account for differences that some folks report. Add in mash out versus no mash out and that could confuse things as well as the amylases continue to chew things up smaller and smaller.

Perhaps the best scenario would be to prepare a grain bill and divide it in half and give one portion to someone with a >90% efficiency and then half to someone with a mid-70's efficiency. Ideally this would be two friends who do the mash by themselves and then ferment in one location and use the same volume of a yeast slurry

If the crush is the primary reason for the efficiency differences, then if the two hypothetical brewers are mashing for the same time, the finer crush will convert faster, and would expose more dextrins for a longer time to get converted into smaller and smaller chains, while in the coarser crush, the large chains are released slower (like the hops additions to DFH 60 min.) so that would provide less time for the amylases to produce more small chains. Or in other words, given a same mash time, a finer crush *could* result in a more fermentable wort (more maltose). Now if you use a coarser crush, I think if you mashed long enough you could eventually reach the same point. In theory, one could convert all of the starch to maltose with either crush (changing mash time) and get the same wort sugar profile

This low efficiency = better

This low efficiency = better beer stuff is just complete bullshit. A well designed lauter tun and and properly conducted mash and lauter should be yeilding in the order of 90% efficiency, and if it does - thats a good thing not a bad thing.


dmtaylor's picture
Well aren't you pleasant this

Well aren't you pleasant this morning!

For what it's worth, I finally conducted an experiment on this, with 16 tasters.  If memory serves, 13 of the 16 could taste a difference between high and low efficiency... but not for the reasons I'd hypothesized.  So I'm inclined to agree that perhaps, just perhaps, efficiency doesn't affect final beer quality as much as I thought.  However, of course, more experiments are needed.

Dave "This is grain, which any fool can eat, but for which the Lord intended a more divine means of consumption. Let us give praise to our Maker, and glory to His bounty, by learning about... BEER!" - Friar Tuck (Robin Hood - Prince of Thieves)