Help on my mash efficiency please!

[cubbiebrewer]

Ok, so I have been brewing all grain semi regularly for the past 3 years. Up until this year I have been doing 5 gallon batches and have never really come across a problem with hitting my target starting gravity. I have now moved up to 10 gallon batches (only 2 so far) and the only changes to my equipment are a new 15 gallon boil kettle and a new square cooler mash tun with a ss braided hose large enough for the batches I'm doing (sorry, don't know the exact size, a little older cooler but I know its big enough).

So this weekend I did a kristallweizen recipe as follows:

12 lbs red wheat
4.5 lbs vienna
4.5 lbs us 2row
.5 lb carahells
1.5 oz hallertau - 60 min
.5 oz hallertau - 10 min
wyeast german wheat 3333

Everything went smoothly. Mashed in 8.5 gal water and settled in at 152 F and only dropped 2 degrees throughout the mash. Sparged with 7 gal water and it settled in at 169 F for an additional 20 minutes. The expected starting gravity was 1.050, but i only managed 1.040. This reading was taken twice with 70 F wort with a hydrometer. The grains were crushed at my lhbs where I have never had any issues.

Any thoughts as to what might have caused this drop in efficiency? The only things I can think of would be a bad grain crush though I feel that is highly unlikely because other than the last two batches, both of which are in the new mash tun, I have never had any issue with a crush of the grains before from my lhbs, or that it is just the cooler (although I don't know what it could be about it since it does its job and holds the heat throughout the initial mash). Any help would be greatly appreciated!

 

[PHDrunk]

Sounds like you've been doing this a while, so I would imagine your process is fairly dialed in. I would guess it's your crush. I also crush at the LHBS and I know they regularly adjust their mill because of frequent use. I'd imagine this is fairly typical of other stores as well. Certainly it will cause fluctuations in efficiency. Another thing to think about: do you typically brew with wheat? Wheat and barley kernels are differently shaped -- it's plausible that the quality of your crush could change with the different type of base grain. Good luck!


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[cubbiebrewer]

I don't typically brew with wheat. I sent a message to the owner of my lhbs to see if he had any thoughts too (guy is an encyclopedia of brew knowledge). I know he was brewing this weekend, so I'm hoping he says his efficiency was off too though I don't expect that to be the case. Are there any other factors with a cooler mash tun, like size vs batch, depth, width, height, or anything like that that can throw off efficiency?

 

[broadbill]

Did you test for starch conversion?

First thing I noted that half of your grist was red wheat, which as zero diastatic power. Therefore you need to rely on the 2-row and Vienna to convert it (as well as itself). I didn't run the numbers, but I would guess you had some problems with conversion.

The other thing I noticed was that you mashed thin (1.5 vs 1.25 qts/lb) which in turn limited the volume you had to sparge with. that could cause efficiency problems as well.

 

[cubbiebrewer]

I did not test for conversion. I understand the need, just have never had these issues before except for the last two batches (previous batch was an ipa, mostly 2 row). Moving forward, I do think it's something I'm going to look into doing though so I do go through all la-dee-da until I get bad readings after it's too late.

I do mash a little thin but once again I've never had an issue with this in the past. So I was just thinking the change in the mash tun would be contributing more than my process. Only my equipment has changed, not how I brew.

Definitely liking the ideas and help though so keep them coming, it's much appreciated!

 

[Natdavis777]

Was your old MLT a cooler with SS braid as well? I know on my old cooler with a braid, I left a decent amount of wort behind due to its inherent dead space. I was able to improve it a big by angling the cooler while doing my runoff to get as much as I could possibly get.


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[Crucial-BBQ]

Ok, so I have been brewing all grain semi regularly for the past 3 years. Up until this year I have been doing 5 gallon batches and have never really come across a problem with hitting my target starting gravity. I have now moved up to 10 gallon batches (only 2 so far) and the only changes to my equipment are a new 15 gallon boil kettle and a new square cooler mash tun with a ss braided hose large enough for the batches I'm doing (sorry, don't know the exact size, a little older cooler but I know its big enough).

So this weekend I did a kristallweizen recipe as follows:

12 lbs red wheat
4.5 lbs vienna
4.5 lbs us 2row
.5 lb carahells
1.5 oz hallertau - 60 min
.5 oz hallertau - 10 min
wyeast german wheat 3333

Everything went smoothly. Mashed in 8.5 gal water and settled in at 152 F and only dropped 2 degrees throughout the mash. Sparged with 7 gal water and it settled in at 169 F for an additional 20 minutes. The expected starting gravity was 1.050, but i only managed 1.040. This reading was taken twice with 70 F wort with a hydrometer. The grains were crushed at my lhbs where I have never had any issues.

Any thoughts as to what might have caused this drop in efficiency? The only things I can think of would be a bad grain crush though I feel that is highly unlikely because other than the last two batches, both of which are in the new mash tun, I have never had any issue with a crush of the grains before from my lhbs, or that it is just the cooler (although I don't know what it could be about it since it does its job and holds the heat throughout the initial mash). Any help would be greatly appreciated!

I know that I will get flamed for this but I have found that a Hochkurz decoction or at least a single decoction to saccrification rest allows me to hit my SG every time when using wheat.

 

[cubbiebrewer]

Was your old MLT a cooler with SS braid as well? I know on my old cooler with a braid, I left a decent amount of wort behind due to its inherent dead space. I was able to improve it a big by angling the cooler while doing my runoff to get as much as I could possibly get.


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The old mash was a cooler as well with a ss braid. It was your basic rectangular cooler. The new one is a rolling square igloo where the spigot is a solid 3 inches from the bottom of the cooler. Because of this I tilt the cooler to attempt to get the rest of the liquid out. Think it would be beneficial to build a PVC manifold for the bottom? Think I might be losing that much sugary wort bc of he braid? I don't notice a noticeable amount of left over liquid and I account for absorption and hit my volume almost spot on.

 

[broadbill]

Was your old MLT a cooler with SS braid as well? I know on my old cooler with a braid, I left a decent amount of wort behind due to its inherent dead space. I was able to improve it a big by angling the cooler while doing my runoff to get as much as I could possibly get.


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Leaving wort behind happens in every set up and should be accounted for. Dead space isn't an efficiency issue; it is an issue of not accurately accounting for volume.

 

[Natdavis777]

.

 

[Natdavis777]

Leaving wort behind happens in every set up and should be accounted for. Dead space isn't an efficiency issue; it is an issue of not accurately accounting for volume.

I agree that there is deadspace in every setup, but if you are not taking that into account, then it will cause an efficiency issue. The OP said he changed to a new MLT, so he might not have his volumes/deadspace dialed in, hence not fully accounted for. So, if he is leaving almost a gallon of fermentable wort in the MLT vs a quart, then the OG will be obviously be lower, and lower his efficiency.

Ive experienced this first hand with my old set up. I averaged 65%, then notcied how much liquid was left behind while I cleaned out the MLT. Since the valve was a good inch off the bottom of my cooler, I started angling the cooler to get more of the first runnings instead of leaving it behind. Alas, my efficiency raised to ~72-75%.

 

[broadbill]

I agree that there is deadspace in every setup, but if you are not taking that into account, then it will cause an efficiency issue. The OP said he changed to a new MLT, so he might not have his volumes/deadspace dialed in, hence not fully accounted for. So, if he is leaving almost a gallon of fermentable wort in the MLT vs a quart, then the OG will be obviously be lower, and lower his efficiency.

Ive experienced this first hand with my old set up. I averaged 65%, then notcied how much liquid was left behind while I cleaned out the MLT. Since the valve was a good inch off the bottom of my cooler, I started angling the cooler to get more of the first runnings instead of leaving it behind. Alas, my efficiency raised to ~72-75%.

You probably also had to boil longer because you collected more runnings after tipping the cooler. Collecting more runnings doesn't mean you had better efficiency. It means you got more sugars into the pot, but also more water. At a percentage, this doesn't change your efficiency.

 

[Natdavis777]

I adjusted my sparge volume after getting more of my first runnings. Since I was able to get a larger volume from the first runnings by adjusting my technique, I was able to reduce my sparge water volume. Less sparge water means less dilution, hence more efficiency


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[Natdavis777]

The first batch I realized this on, yes, I had a larger boil volume. Taking that into account on my next batch, I calculated the % of extra wort I was able to get from my first runnings, and then subtracted that from my sparge volume. So it was trial by process, but the logic is there.

I could leave the cooler level, run off 1.2gal and then batch sparge with 5.8gal to get a 7 gal pre boil volume. Or I could tilt the cooler, get 2 gal first runoff and sparge with 5 gal of water. Obviously the latter will yield a better efficiency


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[cubbiebrewer]

Would the sugars drop to the bottom of the tun over the hour plus for the initial mash? Could that possibly account for the loss in gravity? Like i said my total volume is fine, but if the heavier sugars sink to the bottom, even if I tilt I could be leaving behind precious gravity points if they do actually sink. Just spitballing here. If that's the case, would changing over to a PVC manifold get that extra liquid?

 

[Natdavis777]

I cannot say heavier sugars sink to the bottom. But getting as much as the first runnings as possible will help your efficiency.

Take your MLT and fill it full of water. Keep it level and run it off until it stops. Then measure what is left in the cooler. That's obviously your dead space. Then try the same process but with the MLT tilted to some degree. The extra liquid you are getting by this process is sugar laden wort. Yes, you could just factor the dead space with extra water, but then you are just diluting the remaining wort.

If you are able to reduce your dead space by almost a gallon (just speculating) if say that is significant in terms of upping your efficiency. I've read where some peoples cooler deadspace is around 1.25 gal.

I never used a manifold in my cooler so I can't comment of how well they perform personally, but based on their design and what people have said on this forum, I'd say a manifold would def help out.

If you do go with a manifold, however, then tilting the cooler wouldn't be necessary.

 

[PHDrunk]

You probably also had to boil longer because you collected more runnings after tipping the cooler. Collecting more runnings doesn't mean you had better efficiency. It means you got more sugars into the pot, but also more water. At a percentage, this doesn't change your efficiency.

FWIW, I disagree with your definition of efficiency. Efficiency is a measure of how effectively you converted and transferred sugar from the grains into the kettle (and eventually to the fermenter). Your statement that collecting more runnings does not lead to higher efficiency may be the case, but is is definitely true that more sugar means better efficiency.


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