efficiency

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

z987k

Well-Known Member
Joined
Feb 13, 2007
Messages
3,513
Reaction score
37
Location
Anchorage
Ok, so ever since I've brewed AG, I've always had 70-75% efficiency. Anymore I'm always dead on 71%. I've been ok with this as it really doesn't effect my beer, but I figured I should change it.

So today when I brewed a hefe I took gravity samples every .5 gallon. I though the results were interesting.

First runnings (each number representing a half gallon):
1.085
1.082
1.066
1.065
Now I batch sparge(rubbermaid cooler and SS braid) and here is where the first 2 gallons of hot water was added:
1.030 (notice the massive drop)
1.027
1.024
1.018
Second 2.5 gallons:
1.018
1.017
1.017
1.016
1.016

Recipe was 4lbs german pils, 4lbs wheat, 2lbs honey malt. Mash at 1.33 qt/lb Sparge 1.6qt/lb 175*F water. Single infusion at 155.

So I'm looking at that and it seems there was sufficient conversion and the first running were spot on where they should be. Now on the sparge of the first hot liquor addition, the points drop through the floor so there has to be something wrong with my sparge technique. I pour in the 2 gallons, stir really well, let it sit a few minutes and drain. The only thing I can think of is, let it sit longer and then drain slower.

Anyone want to look at those numbers and conclude something different?
 
It looks like you are not stirring enough before taking the runnings.
If you stir really well, and let it settle for 5 - 10 minutes before vorlaufing and then draining, then the sugars in the wort will be dissolved in the water and the runnings will remain almost constant until you add more water. When you do add more water, the gravity for the next batch of runnings will be lower because the extra water dilutes the sugar concentration.
From your figures, the gravity of each batch drops as the runnings proceed which indicates that the water at the top has less sugars dissolved in it than that at the bottom.
I'd try stirring better, and try to mix it from top to bottom to get an even distribution of sugars in the wort before draining.
You could also increase you sparge water temperature a bit (say 180F). This should not cause any problems providing the grain bed temperature does not exceed 170F.
Edit. Ignore the settling time of 5 - 10 minutes. That's what I usually do, but I don't really think it is required. End edit
-a.
 
I'm really confused. If you batch sparge, the incremental runoff measurements should not change at all. Batch sparging relies on diffusion of sugars into solution. Basically you should be stirring the mash one more time before you vorlauf and runoff. After that, you infuse the batch sparge, stir really well, vorlauf and runoff. I just realized I just basically repeated what ajf said, but it's true so....
 
I guess that I would expect a large drop in the SG between sparges. I mean, you are draining your first wort, which is massively laden with sugar... then adding 2.5 gallons of pure water. MUCH of the sugar was gone with the first runnings right? Then you are diluting what is left in 2.5 gallons of pure water.

I mean some people SINGLE batch sparge and get like 60-65% which means that much of the sugars run with the first runnings.

I was actually surprised to see that your second and third runnings ended and began, respectively, at the same SG... I would think that again, batch sparging, that the ending gravity of one sparge, and begining of another would be much different, because you were diluting what sugar was left, again, in 2.5 gallons of water.

This is all well and good, and I am not a batch sparger, but it seems that with each water infusion the SG would drop significantly.

How is your crush? How is your water? How long are you letting the water sit in the grain before running off? 5 minutes? 10 minutes? 2 minutes? I am not a batch sparger, but I know the water needs to be HOT, the grain bed 165F or so and that the water infusions have to sit for a while, 5 minutes or so, along with a good stir, to get good lauter eff.

I also agree with the above post, when you are batch sparging, the wort in the mash should be pretty homogenous, there should not be a large sugar gradient when running off. Fly sparging is a bit different, but you should see a pretty homogenous runoff.
 
I guess that I would expect a large drop in the SG between sparges. I mean, you are draining your first wort, which is massively laden with sugar... then adding 2.5 gallons of pure water. MUCH of the sugar was gone with the first runnings right? Then you are diluting what is left in 2.5 gallons of pure water.

I mean some people SINGLE batch sparge and get like 60-65% which means that much of the sugars run with the first runnings.

I was actually surprised to see that your second and third runnings ended and began, respectively, at the same SG... I would think that again, batch sparging, that the ending gravity of one sparge, and begining of another would be much different, because you were diluting what sugar was left, again, in 2.5 gallons of water.

This is all well and good, and I am not a batch sparger, but it seems that with each water infusion the SG would drop significantly.

How is your crush? How is your water? How long are you letting the water sit in the grain before running off? 5 minutes? 10 minutes? 2 minutes? I am not a batch sparger, but I know the water needs to be HOT, the grain bed 165F or so and that the water infusions have to sit for a while, 5 minutes or so, along with a good stir, to get good lauter eff.

I also agree with the above post, when you are batch sparging, the wort in the mash should be pretty homogenous, there should not be a large sugar gradient when running off. Fly sparging is a bit different, but you should see a pretty homogenous runoff.

Yes I would think each sparge should be significantly lower, but then after the 2nd and 3rd came up I got confused about it as well and figured that the 1-2 had something wrong with it.

Crush... I could probably go a touch finer without getting a stuck sparge. Not much though. Water is 175*F. That should be plenty warm enough. I give it a good stir, wait probably 2mins and drain. That may be it, I need to wait longer.

Also it could have nothing to do with the sparge technique and more on the crush like you said. With 10lbs of grain, is that 1.085-1.065 high enough? If not, I need to start there. If those numbers aren't high enough the following sure aren't going to be.
Run-off speed should make no difference in batch sparging....

*I'm going to go re-read kaiser's efficiency page.
 
If your crush is that fine already, then I agree... you should be able to pull 80+ percent eff. Perhaps the batch sparge infusions are not getting managed well enough. 2 minutes is not enough. I dont batch sparge, but have done some research and written on the topic... Id say your temp is good, but mix it well and let it sit longer, 5-10 minutes for each sparge. Also, you are right, runoff speed is of little concern.
 
I'm not yet an all-grain brewer, but I've done a few partial mashes. All the other posts have some good suggestions, but here's one I haven't seen mentioned, and I believe it lowered my efficiency on my last batch. I was using a new copper manifold and had checked the dead space in my 5 gallon Igloo cooler MLT to be about 1/2 cup, using only water and just letting the outlet tube drain off into the sink. When I did the first actual mash, with the outlet tube lying on the bottom of the brew kettle to drain, as the runoff approached the end, I lifted the end of the tube out of the wort in the brew kettle to check the flow. What I wasn't thinking about was that the flow rate was much reduced because of the grain in the MLT - there wasn't enough flow to keep the outlet tube filled when I lifted it, and once it emptied, this allowed air into the tube, breaking the siphon, and leaving a lot more than the expected 1/2 cup of liquid in the MLT, effectively increasing the dead space. The fact that you were taking frequent hydro samples makes me wonder if you might have done the same thing. Of course, this wouldn't explain your efficiency problems with earlier batches where you weren't taking samples, unless you weren't keeping the end of the outlet tube submerged until the siphon broke normally from air entering from the inside of the MLT.
 
I'm not yet an all-grain brewer, but I've done a few partial mashes. All the other posts have some good suggestions, but here's one I haven't seen mentioned, and I believe it lowered my efficiency on my last batch. I was using a new copper manifold and had checked the dead space in my 5 gallon Igloo cooler MLT to be about 1/2 cup, using only water and just letting the outlet tube drain off into the sink. When I did the first actual mash, with the outlet tube lying on the bottom of the brew kettle to drain, as the runoff approached the end, I lifted the end of the tube out of the wort in the brew kettle to check the flow. What I wasn't thinking about was that the flow rate was much reduced because of the grain in the MLT - there wasn't enough flow to keep the outlet tube filled when I lifted it, and once it emptied, this allowed air into the tube, breaking the siphon, and leaving a lot more than the expected 1/2 cup of liquid in the MLT, effectively increasing the dead space. The fact that you were taking frequent hydro samples makes me wonder if you might have done the same thing. Of course, this wouldn't explain your efficiency problems with earlier batches where you weren't taking samples, unless you weren't keeping the end of the outlet tube submerged until the siphon broke normally from air entering from the inside of the MLT.

No I don't mess with the mash once I start draining.
The samples were all taken with a refractometer out of the 1/2 gallon bucket I was draining into once it was full.
 
I think that 2 minutes is plenty of time. I double batch sparge and I vorlauf immediately after I stir (which takes a couple minutes) and then drain. I have been consistently getting 88 percent efficiency. My friend does not stir when he batch sparges. He is careful to not disrupt the grain bed when he adds water until the grain bed is covered and then he drains it off. He too gets around 90 percent efficiency using this method.

My theory is that it doesn't take much to dissolve the sugars if they are converted.

What is your mash pH? We both use 5.2 stabilizer. We also both use barley crushers FWIW. We've been joking that 5.2 stabilizer + barley crusher = 90 percent efficiency.
 
I didn't test the pH of this mash. That was stupid if I was using it as a troubleshooting batch.
 
ok, re-read kaiser's wiki on mash and lauter eff.
based on this thread: https://www.homebrewtalk.com/f36/first-wort-gravity-mash-efficiency-68555/
and this spreadsheet: http://braukaiser.com/documents/efficiency_calculator.xls

Edit:

Ok I found this cool spreadsheet on kaiser's page.
I plugged in my numbers and here's what it spit out:

Mash Efficiency: 99% (mash pH, crush are obviously not a problem)
Efficiency into Kettle: 92%
Lauter Efficiency: 87% - I doubt this
Efficiency lost in wort held back by spent grain: 12%
Extract Potential that made it to the boil kettle: 73%

I'm not sure what to make of that, because it seems wrong.... All that doesn't add up to the 71% eff I got. The mash efficiency lets me know it's not a mash problem rather a getting the sugar into my pot problem.
Anyone else have a take on this?

I'm brewing Wednesday or Thursday and I'll take all the same readings, but this time have the sparge water at 180 and let it sit 15mins after vigorously stirring before sparging. That's all I can think of.
 
I've changed my mind about letting the mash settle after stirring. That's what I do, but I don't think it has any effect. I updated my post to say this. Sorry.
I ran your numbers through Kaiser's spreadsheet, and came up with 84% mash efficiency. (That was taking the mean gravity for your first runnings.)

-a.
 
I've changed my mind about letting the mash settle after stirring. That's what I do, but I don't think it has any effect. I updated my post to say this. Sorry.
I ran your numbers through Kaiser's spreadsheet, and came up with 84% mash efficiency. (That was taking the mean gravity for your first runnings.)

-a.

Ok, see I didn't know if he really meant first wort into kettle literally, or not.. so I took it literally and used only the very first number. If that is not the case then yes there is significant problems with the mash. Of course not doing so would make more sense since it would get the number down to what I expected it to say.
Which is it?
 
If you get constant gravity for each running, it wouldn't make any difference, except right at the start of the running when you could be collecting liquid from under a false bottom, or already in the plumbing. As your gravity is decreasing, you have to calculate the average gravity

-a.
 
ok well I need to figure out what to change with the next batch and it can really only be one thing at a time if I want to spot the problem. I was thinking crushing even finer and risking a stuck sparge OR mashing thinner, like around 2qt/lb that everyone is raving about. Then I will check the mash ph and if that's off adjust with some acid.
Of course with the thinner mash I should be able to crush finner without risking a stuck sparge as much.
 
People are saying that siting time doesn't matter, but in Death Brewer's simple stovetop AG thread, when he went from 5 minutes of rest to 10 minutes, he bumped up quite a few percentage points.

I'd give it a try if I were you. I let mine sit that little extra bit to give time for the sugars to leach out form the grain bed some; if the first runnings were say 64, then everything including the water in the grain was 64. If you just pour more water in and don't give it enough time to equalize out and pull the sugar from the grain bed, then you're not getting everything that you should be.

Either way, waiting 5 more minutes isn't really going to kill your brew day....

Still, nothing at all wrong with 70%; that's what most recipes are formulated for, so you're really hitting recipes right on! :ban:
 
I think you've made an excellent start by collecting and analyzing data that can give you an insight into what could be improved. This data has shown that your gravity decreases substantially during each of the runnings, which it shouldn't if the wort is stirred enough before draining.
Having established this from the data you have collected, I would suggest that you work on that problem before introducing new variables such as a finer crush or thinner mash.

-a.
 
I think you've made an excellent start by collecting and analyzing data that can give you an insight into what could be improved. This data has shown that your gravity decreases substantially during each of the runnings, which it shouldn't if the wort is stirred enough before draining.
Having established this from the data you have collected, I would suggest that you work on that problem before introducing new variables such as a finer crush or thinner mash.

-a.

yeah I know I should not introduce new variables, but I want to see it go up and I'm impatient on that. I can probably do 2 brew days in the next week or so, but then I'll have all my carboys full. Damn sour beers. :)

I was considering doing some tests with like a pound of grain, that way i can introduce a new variable each time and see how it changes. (and get some wort to make starters with)
 
I too use pH 5.2 stabilizer although I cannot comment on its effectiveness because I added a bunch of different procedures when I started using this process. What I can say is that I increased my efficiency from roughly 55% to 91% by implementing the following.

1. Performing a double batch sparge with hotter water. I was previously using sparge water at 168 before adding it to the grain and not a grain bed temp of 168. I was also doing a single sparge.

2. I began using pH 5.2 stabilizer which stabilized the pH from about 5.0 to 5.2 using the litmus paper sold at LHBS. On my next batch I will be using my newly acquired pH meter which will help to clarify with more accuracy in readings.

3. I allowed a longer time for conversion 90 minutes as compared to 60 minutes. I don't think this made much difference based on iodine tests showing near conversion in about 30 minutes after starting mash.

4. I STARTED CRUSHING MY OWN GRAIN. I do not have a grain mill but I was relying on the advice of my local home brew shops. Everytime I mill grain there they look at me like I have 2 heads because the grain is actually crushed like it should be. I always get the comment "You don't want to mill it that fine you're going to get a stuck sparge". I then tell them I never have and I have milled it finer than this in the past. They have no idea what type of system I have and whether I have a copper manifold, false bottom or stainless braided hose. I think my copper manifold is very resistant to a stuck sparge.

5. I allowed 10-15 minutes for the sparge water to dissolve or allow more conversion in the grain bed.


I drain at a moderate pace and the cooler is empty of sparge water in about a minute. I think the things that gave me the best increase in effeciency were 1, 4 and 5. As I get more AG batches under my belt I will try removing some variables from my process to see what actually makes a difference. It's hard not to use a "shotgun" approach when your effeciency is poor and you want to correct it now and not 4 batches from now. I hope that might help a little.
 
hot sparge water, 15 min rest, s l o w drain.

Everyone keeps saying "hot sparge water" and I am assuming that means 170º. But my question is, do you heat your HLT/sparge water up to 170º THEN sparge? Once that 170º hits the grain bed, the temp is going to be well below 170º. So should you heat your sparge water up to 185º, so when it hits the grain bed the temp will rest at 170º??? Is that what you guys are doing?

How long should it take you to drain your mashtun when sparging? Mine takes about 30-40 min and I have been getting terrible efficiency. Ball valve is about 1/4 open.
 
First of the changes, I only adjusted mash pH. I was at 6.4 at mash in, adjusted to what ended up at 5.1 (overshot a bit) and gained 8 points from 71% eff to 79%. Next I will keep the sparge water in the mlt for 15mins instead of the roughly 2. After that, as fine a crush as I can possibly do. I'll just keep adjusting things until I hit 85ish I think.
 
Everyone keeps saying "hot sparge water" and I am assuming that means 170º. But my question is, do you heat your HLT/sparge water up to 170º THEN sparge? Once that 170º hits the grain bed, the temp is going to be well below 170º. So should you heat your sparge water up to 185º, so when it hits the grain bed the temp will rest at 170º??? Is that what you guys are doing?

How long should it take you to drain your mashtun when sparging? Mine takes about 30-40 min and I have been getting terrible efficiency. Ball valve is about 1/4 open.

Most common method of sparging is to start with a mashout addition, which is usually over 200F. It is meant to bring the entire mash up to 168 in order to denature the enzymes. So, after the mashout, your mash is somewhere around 168, and that is the best temperature for your sparge water.

I don't usually mashout. I mash for 60-90min, then sparge away with 170 water. I am guessing that all enzyme action is done by then, so no point in denaturing. I overshoot my OG all the time, though, so maybe I'm wrong.
 
So tonight I adjusted pH, crushed real fine, let the sparge water sit 15mins.... and wow 89% eff. Now to go back and figure out what one did it.... although I don't know how much I care if I can repeat the 89% with the same procedure.
6lbs MO
.5lb crystal
1.040OG.
 
I don't understand how your first runnings had a decreasing gravity as they ran off. The whole mash should be homogeneous.

In any case, at least you're getting it dialed in. That spreadsheet of Kaiser's is a big help to determine if it's mash eff or lauter eff. It seems to me that as long as you're getting close to 98%-99% mash eff then there's no need to crush any finer and doing so might even be detrimental to wort quality (more shredded husks).

Also, to measure the 'first runnings' gravity (to determine mash efficiency) I just pull a sample straight out of the mash right before I lauter/sparge (and after a quick stir). I know exactly how much water and grain is in the mash and there's no dilution factor due to the hot water I have to pre-fill my lauter tun with (I fly-sparge in a Zapap).
 
Most common method of sparging is to start with a mashout addition, which is usually over 200F. It is meant to bring the entire mash up to 168 in order to denature the enzymes. So, after the mashout, your mash is somewhere around 168, and that is the best temperature for your sparge water.

I don't usually mashout. I mash for 60-90min, then sparge away with 170 water. I am guessing that all enzyme action is done by then, so no point in denaturing. I overshoot my OG all the time, though, so maybe I'm wrong.
Actually you don't fully denature all the enzymes even @ 168 F. The alpha-amylase is still working.

I think Kaiser has done experiments with cold-water sparges and his eff didn't take the hit you would expect. Here's a comment he made in this thread:
Kaiser said:
Just to clarify my claim: It (the sparge water temp) should not affect your efficiency if all the conversion is done in the mash. But especially when mashing thick you may not convert all the starches in the mash and subsequent conversion happens during lautering. This is when you see the sparge temp affecting efficiency. The hotter the faster and more complete that conversion will be.

Anymore I don't really sweat getting the mash/sparge all the way up to 168-170. As long as it's over 160 or so it doesn't seem to make any difference (and I haven't tried <160 F). And getting it over 160 F is merely to set the fermentablity of the wort (i.e. denaturing the beta-amylase) not really anything to do with efficiency.
 
Actually you don't fully denature all the enzymes even @ 168 F. The alpha-amylase is still working.

I think Kaiser has done experiments with cold-water sparges and his eff didn't take the hit you would expect. Here's a comment he made in this thread:

Anymore I don't really sweat getting the mash/sparge all the way up to 168-170. As long as it's over 160 or so it doesn't seem to make any difference (and I haven't tried <160 F). And getting it over 160 F is merely to set the fermentablity of the wort (i.e. denaturing the beta-amylase) not really anything to do with efficiency.

Hmmm that's interesting, I would think the solubility of sugar with increased temperature would be a factor.



I also don't really know why I got decreasing gravity from rthe first runnings. Really makes no sense, but that is what the refract said. I'll repeat it again here with the next brew and see what happens.
 
Back
Top