Negatives of Low Mash Efficiency

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DoubleWideBrew

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Besides having to spend a little more money on grains to make up for a low mash efficiency, are there any other downsides to having a low efficiency?
EDIT: I use BIAB with double milled grains and get ~80% which is typical. I just wanted to see what the reasons are for trying to bump the % up. From the replies, my consensus is that another benefit of higher efficiency is that if you are trying to be very consistent from batch to batch, bumping it up helps (~80% +/-5% compared to ~90 +/-1%).
 
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downzero

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From my perspective, it's been more important to have a good estimate of efficiency rather than hit a certain number. If you don't know your system, and over or under shoot your numbers, the beer is going to turn out different than expected. That would be my primary concern rather than achieving some number someone else says you ought to be able to achieve.

The simple answer to the question asked is "no."

The more complicated answer is that if you don't have a good estimate of your efficiency, you won't be able to develop recipes and deliver the expected product to the glass.
 

IslandLizard

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How low do you find acceptable? If mash efficiency is anywhere under 75% I would find the cause and fix it.
2 most common causes of low mash efficiency:
  • Grain is milled too coarsely ==> Mill finer
  • Large deadspace in the mash vessel; it doesn't drain all the wort ==> Lower drain, tilt vessel when draining, or find other solution
 

dmtaylor

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How low do you find acceptable? If mash efficiency is anywhere under 75% I would find the cause and fix it.
2 most common causes of low mash efficiency:
  • Grain is milled too coarsely ==> Mill finer
  • Large deadspace in the mash vessel; it doesn't drain all the wort ==> Lower drain, tilt vessel when draining, or find other solution
I do tend to agree.... it doesn't take a whole lot of effort to get at least 70% efficiency I would say. If lower than that, you're not trying very hard.
 

mongoose33

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I have to agree. I would *MUCH* rather have known repeatability, so I can expect certain numbers, regardless of their magnitude, instead of chasing another few % points for anything.
I agree, though I would add predictability so that it's reasonably likely new recipes will produce what the brewer is after.

I think it's normal and natural for new brewers to be focused on numbers--it's the one objective measure of what they're doing. I certainly was focused on them, everything from efficiency to ABV to SRM (less so) to....

I can't remember the last time I calculated efficiency. Instead it's more along the lines of "I should get something like this gravity number" as an indicator I've produced what I was after.

It was only after a while I became more concerned with how the beer tasted, and how others perceived it--as a measure of its quality--than the numerical specifics.

**********

This is somewhat of a tangent. There is probably nobody on homebrewtalk who is more focused on things like measuring variables correctly. I'm a scientist by training, and for better or worse it shows through in a lot of the things I do.

And yet....while that focus was evident to the extreme early in my brewing career, it has taken a back seat to....judgment and intuition. That is, brewing more as art, and not as much as science. If I'm trying to do a new recipe, I'm kind of using my intuition to guess what would work--hops, timing, mash temps, step mash, malts, fermentation temps, etc.

I know a lot of people use Beersmith and similar to model their recipes. I don't, and I have a current subscription to Beersmith 3. But I don't really care about SRM, the IBUs, and so on. And I've never put in my equipment profile. When I brew, my subconscious and intuition rule the day.

I *do* record what I do, so if I hit on something great I can reproduce it. But for me, this is more art than science.

YMMV.
 

Alex4mula

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I took notice of my low efficiency and wanted to improve. Lucky for me it was the lhbs crush. Got a crusher and went from 70s to 90s on mash conversion and now I hit the recipe OG almost spot on.
 

balrog

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I agree, though I would add predictability so that it's reasonably likely new recipes will produce what the brewer is after.

I think it's normal and natural for new brewers to be focused on numbers--it's the one objective measure of what they're doing. I certainly was focused on them, everything from efficiency to ABV to SRM (less so) to....

I can't remember the last time I calculated efficiency. Instead it's more along the lines of "I should get something like this gravity number" as an indicator I've produced what I was after.

It was only after a while I became more concerned with how the beer tasted, and how others perceived it--as a measure of its quality--than the numerical specifics.

**********

This is somewhat of a tangent. There is probably nobody on homebrewtalk who is more focused on things like measuring variables correctly. I'm a scientist by training, and for better or worse it shows through in a lot of the things I do.

And yet....while that focus was evident to the extreme early in my brewing career, it has taken a back seat to....judgment and intuition. That is, brewing more as art, and not as much as science. If I'm trying to do a new recipe, I'm kind of using my intuition to guess what would work--hops, timing, mash temps, step mash, malts, fermentation temps, etc.

I know a lot of people use Beersmith and similar to model their recipes. I don't, and I have a current subscription to Beersmith 3. But I don't really care about SRM, the IBUs, and so on. And I've never put in my equipment profile. When I brew, my subconscious and intuition rule the day.

I *do* record what I do, so if I hit on something great I can reproduce it. But for me, this is more art than science.

YMMV.
I'm a long way from "chef", knowing what will work for flavor combo; I'm still much more a "cook", learning what I like from others' recipes.
 

bobeer

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How low is low? I'm super cheap when it comes to hobbies so low efficiency would drive me crazy. Maybe mill a little finer and make sure you're stirring the mash well to break up any dough balls. You can also get an iodine kit for cheap to make sure you have full convergence in your mash before you pull it.
Are you using a mash tun or BIAB? Any details of you setup will help troubleshoot if you want to try and solve the issue.
 
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DoubleWideBrew

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From my perspective, it's been more important to have a good estimate of efficiency rather than hit a certain number. If you don't know your system, and over or under shoot your numbers, the beer is going to turn out different than expected. That would be my primary concern rather than achieving some number someone else says you ought to be able to achieve.

The simple answer to the question asked is "no."

The more complicated answer is that if you don't have a good estimate of your efficiency, you won't be able to develop recipes and deliver the expected product to the glass.
Thanks for all of the answers. I use a BIAB and have an efficiency ~80% with double milled grains. I'm still a beginner and won't be at the point of needing to get a very consistent batch any time soon, so it's good to know I don't need to stress about it too much or rush to buy a recirculating pump.
 
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DoubleWideBrew

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How low is low? I'm super cheap when it comes to hobbies so low efficiency would drive me crazy. Maybe mill a little finer and make sure you're stirring the mash well to break up any dough balls. You can also get an iodine kit for cheap to make sure you have full convergence in your mash before you pull it.
Are you using a mash tun or BIAB? Any details of you setup will help troubleshoot if you want to try and solve the issue.
I do BIAB with double milled grains and get ~80% efficiency. I am comfortable with 80%, but I wanted to make the post to double check to see if I was missing out on any big positive aspects on a higher %.
 

downzero

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I do BIAB with double milled grains and get ~80% efficiency. I am comfortable with 80%, but I wanted to make the post to double check to see if I was missing out on any big positive aspects on a higher %.
I smash the crap out of mine and my efficiency is much lower than that. I pay strict attention to volume, ph, water treatment, etc., but I have never seen that kind of efficiency. I have no clue why as of now; perhaps I'll figure it out. For now I focus on fine tuning my process to make sure I'm measuring efficiency properly. Over time if it goes up, so be it, if not, oh well.
 

balrog

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Most missed mash measurements of efficiency are due to volume mis-measurement or grain crush. If you aren't measuring volumes carefully you'll mis-measure most efficiency math.
 
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