For my bigger beers I bought a 10-gallon Igloo converted cooler mash tun that I set up the same as my 5-gallon with a bazooka filter. I have had no trouble hitting OG with the 5 gallon one that I've used for many years, but on the 10 gallon one I am missing it by 10 to 20 points. Any suggestions?
Losing efficiency when switched to a 10 gallon mash tun
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If nothing else about the recipe has changed from how you made it in your 5 gallon tun (grain amount, crush, water temp, water amount etc), I am betting that the increased headspace is causing the mash to cool to fast in the first 15 minutes which of course are the most crucial for conversion. My advice is to pre heat the tun before mashing in to help negate the thermal loss due to the increased mass. Of course, I am basing that on my above notion that everything else remained the same.
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aharri1
In Rembrance 6/2023
I did notice that I lost a lot more heat with the bigger mash tun. the second time I used it on a 20lb grain bill I heated the strike water to 173 to preheat for 5 min with the volume and kept a probe on it. The strike temp was supposed to be 167 which I hit so I poured the grains and mashed in. When I checked the mash 10 minutes later it was 147 so I'm guessing I need to raise my strike water temperature to preheat the tun with a higher temperature to account for headspace loss. I did boil a quarter gallon of water and got it the 150 after stirring but like you said if the crucial time is the first 15 minutes I lost conversion because of that. I guess I need to dump water around 177 into it to preheat it to account for loss!! Thanks !!
Fly sparge, batch sparge, or no sparge?
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Brew on
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aharri1
In Rembrance 6/2023
Fly spargeFly sparge, batch sparge, or no sparge?
Brew on
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aharri1
In Rembrance 6/2023
Right on
I bet you got better efficiency with a 20 lb. grain bill in the 10 g. cooler than you could have got with the same grain bill in the 5 g. cooler. 
When I changed my mash tun from 5 to 10 gallons, it took me a couple of brews to get used to the difference, but my efficiency improved from about 75% to 82%, and it took considerably less time to sparge. However, I used a false bottom as opposed to a bazooka tube.
Alan.
When I changed my mash tun from 5 to 10 gallons, it took me a couple of brews to get used to the difference, but my efficiency improved from about 75% to 82%, and it took considerably less time to sparge. However, I used a false bottom as opposed to a bazooka tube.
Alan.
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aharri1
In Rembrance 6/2023
I'm considering getting a false bottom to see what the difference is!!I bet you got better efficiency with a 20 lb. grain bill in the 10 g. cooler than you could have got with the same grain bill in the 5 g. cooler.
When I changed my mash tun from 5 to 10 gallons, it took me a couple of brews to get used to the difference, but my efficiency improved from about 75% to 82%, and it took considerably less time to sparge. However, I used a false bottom as opposed to a bazooka tube.
Alan.
And I may have. I just missed my OG by 13 points but I think that was due to the temperature difference I didn't account for
Your lower efficiency was definitely affected by it being a bigger beer. For a constant pre-boil volume and process, lauter efficiency drops with increasing grain bill size. There is nothing you can do about this, except increase your pre-boil volume and boil-off, but it's still a hard slog to make up for the larger grain bill weight. For example if you compare a 10 lb grain bill vs. a 20 lb grain bill for a 5.5 gal post-boil volume, with 1 gal/hr boil-off. For the 10 lb grain bill, you need 6.5 gal pre-boil, and a one hour boil. To get the same lauter efficiency with the 20 lb grain bill, you would need 13 gal pre-boil, and 7.5 hours to boil off the 7.5 gal required to get down to 5.5 gal post-boil.
The chart below shows how lauter efficiency varies with grain bill weight to pre-boil volume ratio for no-sparge and batch sparge. A very well done fly sparge can get you 2-3 percentage point higher lauter efficiency than a 3X batch sparge @ 0.12 gal/lb grain absorption, but a poorly done fly sparge (with lots of channeling for example) can have lower lauter efficiency than a single batch sparge.
A braid pickup is not the optimal choice for fly sparging, and the larger diameter the MLT, the worse it will perform in general (has to do with flow length and resistance to get to the pickup.) For optimal fly sparge performance you want a false bottom, as this drops the flow resistance to the pickup to almost zero. So, the braid pickup may perform worse on your larger MLT.
To really understand what is happening, you need to measure your conversion efficiency (use the method here), calculate your mash efficiency (using any of the on-line calculators), and then calculate your lauter efficiency as:
Brew on
The chart below shows how lauter efficiency varies with grain bill weight to pre-boil volume ratio for no-sparge and batch sparge. A very well done fly sparge can get you 2-3 percentage point higher lauter efficiency than a 3X batch sparge @ 0.12 gal/lb grain absorption, but a poorly done fly sparge (with lots of channeling for example) can have lower lauter efficiency than a single batch sparge.
A braid pickup is not the optimal choice for fly sparging, and the larger diameter the MLT, the worse it will perform in general (has to do with flow length and resistance to get to the pickup.) For optimal fly sparge performance you want a false bottom, as this drops the flow resistance to the pickup to almost zero. So, the braid pickup may perform worse on your larger MLT.
To really understand what is happening, you need to measure your conversion efficiency (use the method here), calculate your mash efficiency (using any of the on-line calculators), and then calculate your lauter efficiency as:
Lauter_Efficiency = Mash_Efficiency / Conversion_Efficiency
If your conversion efficiency is less than 90%, you need to work on that. Finer crush is the biggest help, and longer mash times are a distant second. Other variables like precise pH and temp control are much less important that crush and time (w.r.t. conversion efficiency.) If your lauter efficiency is not beating a single batch sparge, then you are better off batch sparging than fly sparging. Or, you could try to improve your fly sparge game.Brew on
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aharri1
In Rembrance 6/2023
Thanks a lot for the info! I'm going to check out the conversion math by itself I use beersmith 3 and I think I'm just going to get a false bottom for the bigger mash tun between now and my next brew! I'll just have an extra bazooka in case I need one [emoji3] .Your lower efficiency was definitely affected by it being a bigger beer. For a constant pre-boil volume and process, lauter efficiency drops with increasing grain bill size. There is nothing you can do about this, except increase your pre-boil volume and boil-off, but it's still a hard slog to make up for the larger grain bill weight. For example if you compare a 10 lb grain bill vs. a 20 lb grain bill for a 5.5 gal post-boil volume, with 1 gal/hr boil-off. For the 10 lb grain bill, you need 6.5 gal pre-boil, and a one hour boil. To get the same lauter efficiency with the 20 lb grain bill, you would need 13 gal pre-boil, and 7.5 hours to boil off the 7.5 gal required to get down to 5.5 gal post-boil.
The chart below shows how lauter efficiency varies with grain bill weight to pre-boil volume ratio for no-sparge and batch sparge. A very well done fly sparge can get you 2-3 percentage point higher lauter efficiency than a 3X batch sparge @ 0.12 gal/lb grain absorption, but a poorly done fly sparge (with lots of channeling for example) can have lower lauter efficiency than a single batch sparge.
View attachment 593374
A braid pickup is not the optimal choice for fly sparging, and the larger diameter the MLT, the worse it will perform in general (has to do with flow length and resistance to get to the pickup.) For optimal fly sparge performance you want a false bottom, as this drops the flow resistance to the pickup to almost zero. So, the braid pickup may perform worse on your larger MLT.
To really understand what is happening, you need to measure your conversion efficiency (use the method here), calculate your mash efficiency (using any of the on-line calculators), and then calculate your lauter efficiency as:
Lauter_Efficiency = Mash_Efficiency / Conversion_EfficiencyIf your conversion efficiency is less than 90%, you need to work on that. Finer crush is the biggest help, and longer mash times are a distant second. Other variables like precise pH and temp control are much less important that crush and time (w.r.t. conversion efficiency.) If your lauter efficiency is not beating a single batch sparge, then you are better off batch sparging than fly sparging. Or, you could try to improve your fly sparge game.
Brew on
NineMileStyle
Incredibly Handsome
I had efficiency issues when I went to 10g's also...Slowing my sparge down was the fix for me.
augiedoggy
Well-Known Member
Ive seen a few folks make a lid that sits on the grain bed inside the cooler out of foil wrapped foam or something to that effect...
I use a 16gallon kettle as my mash tun with lots of headspace and still net over 90% eff so the size isnt the issue, of course I dont have the headspace issue since I use a rims and recirculate at a low 1.5gpm to avoid channeling.
goodluck!
I use a 16gallon kettle as my mash tun with lots of headspace and still net over 90% eff so the size isnt the issue, of course I dont have the headspace issue since I use a rims and recirculate at a low 1.5gpm to avoid channeling.
goodluck!
