efficiency question

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autonomist3k

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I just got a mash efficiency of 78% which I'm pretty happy with.
but I got a brewhouse efficiency of 64.5% which seems low to me.
My OG was 5 pts lower than expected. I was calculating for 70% brewhouse efficiency. I batch sparge btw.

My question is, is 64.5% a decent over efficiency? what would you say is average?
 
Most recipes are built around 75%. If you came in 5 points under your og,chances are the 64% is closer than 78% for your efficiency.


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I batch sparge as well but split my sparge in half for two runnings. I usually run around 82% efficiency. So if I'm using someone else's recipe I come in a few points higher on my OG.


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No, I'm saying that my MASH efficiency is 78%, so my mash isn't the culprit.
But my overall efficiency is 64%, so there's something wrong in my process other than my mash.



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I'm thinking my boil off rate is the problem, but I'm just curious if 64% overall is bad for batch sparging.


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Where are you getting the 64% from? Is that derived from how many gallons hit the fermentor? If that's the case, sounds like you have a lot of dead space in your kettle. Are you using whole hops or pellet? Whole hops absorb wort and will also lower your overall efficiency. Boil off should have no impact on your efficiency. You're not boiling off sugar, just water. Whether you have a higher OG (less water) or a lower OG (more water) the amount of sugar you extracted remains the same.
 
Boiloff shouldn't affect it because that doesn't affect sugar in the pot. Do you have dead space in the mash tun or somewhere else?

How large was your batch and what was expected? Keep in mind, if you get 6 gallons of 1.050 and you expected 5 of 1.060, you don't have an efficiency problem.
 
I'm using beersmith which calculates brew house efficiency, it takes everything into account, mash efficiency, dead space in mash tun and kettle, and adding your measured OG effects it also.
I use pellet hops.
It's a 2.5 gallon batch, and I got the correct amount of wort.

I'm using my equipment that I use for 5 gallon batches, I bet the dead space effects the smaller batches more.


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Ok. So are you saying that you had a calculated mash efficiency of 78% which should have given you an OG of 1.067 but you ended up with 1.062 instead?
 
Yeah the mash efficiency was 78, which is better than beersmith was estimating. So somewhere in my process after the mash my overall efficiency went down.


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Yeah the mash efficiency was 78, which is better than beersmith was estimating. So somewhere in my process after the mash my overall efficiency went down.


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I assume you're calculating your mash efficiency by pre-boil gravity, so you're saying that your pre-boil gravity was higher than anticipated, but your OG was lower than anticipated. If you have a certain amount of sugar in a certain amount of water and start boiling, the concentration of the sugar will increase predictably. If the numbers come out wrong, it seems there are only a few possibilities:

1 - You left more wort in the kettle (trub or loss to chiller or miscalculated boil-off or ???) than Beersmith calculated, meaning the sugars were spread among more water than Beersmith expected.

2 - One or both of your gravity readings was wrong - maybe a temperature issue, maybe an issue with poorly-mixed wort (although that's more often an extract issue), maybe some other reason.

3 - You forgot to make a late fermentible addition. Perhaps you forgot to add a pound of extract, doing a sweet stout and forgot the lactose at ten minutes, doing an IPA and forgot the half pound of dextrose you wrote into the recipe, etc.

If it's not one of these, I'm stumped.
 
I think it's #1.
I need to boil off more, but if I do I'm going to have less volume, so I need to figure out how to get beersmith to account for that. that part is confusing me so far.
 
I think it's #1.
I need to boil off more, but if I do I'm going to have less volume, so I need to figure out how to get beersmith to account for that. that part is confusing me so far.

Have you set up and dialed in your Beersmith equipment profile? It has variables for trub and chiller loss, boil-off rate, and many other useful tools for getting what you expect out of your brews. I'm still new (8 batches under my belt) and only recently discovered just how much customization one needs to do in order to really get that profile dialed in - I'm used to planning a 5.5 gallon recipe and ending up with 4.5 gallons in the fermenter - but now that I know a bit more about equipment profile customization, I'm hoping to get things dialed in better for future brews.
 
Yea I've messed with those settings over and over again, I've been getting closer, but not quite good enough yet.
 
You've definitely got some numbers off somewhere in your software. If you actually had a 78% mash efficiency and were expecting to get 2.5 gallons of 1.067 OG wort, then that means that you extracted 167.5 total gravity points from the mash. Doing the math backwards, that puts 100% extraction efficiency at ~ 214. Instead, you ended up with 2.5 gallons of 1.062 gravity wort, which is 155 total gravity points. 155/214 = 72% So you're not losing as much as you thought you were. A kettle dead space of 0.2 gallons (a little less than a quart) would easily explain your overall drop in efficiency. In short, your efficiency as of this moment is 72%. It will drop a little bit more due to trub and minor volume loss to the fermentor. There's still a little room to improve your efficiency, but you're not doing bad at all. I wouldn't fret. Might want to tweak the software though.
 
+1 to BBL. I highly recommend taking the time to learn and understand gravity points for any homebrewer. Easy way to figure efficiency yourself and to make fermentable adjustments on the fly if you undershoot your og


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wow thanks! I need to figure out how to do that math like that.

It's not too hard. It's very helpful to know how to do all the math yourself before you start relying on software. Makes it a lot easier to troubleshoot, avoid simple mistakes and to make the necessary adjustments to the software. What I did was just look at the efficiency that you reported.

Efficiency is the amount of sugar you extracted from the mash compared to the maximum yield. The base malt I use, for example, has a maximum yield of 38 points per lb. So, If I mash 5 lbs of only that grain I would have a maximum yield of 38*5 =190 gravity points. Let's say I do a mash and I end up with 2.5 gallons of 1.057 gravity wort. In this case, I have 57 gravity points per gallon or wort. To figure out how many total gravity points I extracted from the mash, I would multiply 57 times the total number of gallons. 57 * 2.5 = 142.5 total gravity points. My max yield was 190, so to figure out my efficiency I divide what I actually got by what I could have gotten. 142.5 / 190 = 75% So the mash efficiency was 75% in this example. To keep going and track later losses in efficiency, just measure how many gallons made it to the fermentor and your OG. Do the same math to figure out how many total gravity points you have at that time and divide it by your max yield again. Say I ended up with 2.5 gallons in the fermentor with an OG of 1.055. 55*2.5 = 137.5 - 137.5 / 190 = 72% So the overall efficiency post boil was 72%.
 
That is extremely helpful, thanks!
I'm going to go back and check my previous recipes to see how I've improved over time.

So it sounds to me that it's safe to say that overall efficiency is always going to be less than mash efficiency. so I don't feel too bad about my last brew, it just sucks that I didn't get the hop utilization that I planned for.
 
That is extremely helpful, thanks!
I'm going to go back and check my previous recipes to see how I've improved over time.

So it sounds to me that it's safe to say that overall efficiency is always going to be less than mash efficiency. so I don't feel too bad about my last brew, it just sucks that I didn't get the hop utilization that I planned for.

Correct. You're overall efficiency will always be less than your mash efficiency.
 
Ok, this is all starting to make sense now.


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I went over my last brew and sure enough, my overall efficiency wasn't that bad, I'm sure now that it's because of the fact that it was a 5 gallon batch vs this recent 2.5 gallon batch, The percentage that's taken away from efficiency due to dead space in the equipment makes a bigger difference on smaller batches.
My mash efficiency on the 5 gallon batch was worse though, but that's because I made some improvements with this most recent batch, I adjusted my grain mill, sparged slower, and made sure to stir pretty good after adding sparge water.

At this rate my next 5 gallon batch should be the best I've done so far efficiency wise.
 
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