For those of you using a 10Gal cylinder type cooler for a mashtun, this is the mash thickness required to fit the most grains in. I was tired of calculating it each time so I made this little chart for quick reference.
If you are like me, you want to make as much beer as you possibly can. For all the work and planning that is involved with all grain, getting the most beer that your system/setup will allow (without affecting the quality or target OG) is key.
1.25 qt water/lb grain (2.6 liters/kg) mash thickness = 25.49 lbs grains max for 10 gal mashtun (ideal mash thickness for most brews, IMO)
1.20 qt water/lb grain (2.5 liters/kg) mash thickness = 26.31 lbs grains max for 10 gal mashtun
1.15 qt water/lb grain (2.4 liters/kg) mash thickness = 27.22 lbs grains max for 10 gal mashtun
1.10 qt water/lb grain (2.3 liters/kg) mash thickness = 28.18 lbs grains max for 10 gal mashtun
1.05 qt water/lb grain (2.2 liters/kg) mash thickness = 29.20 lbs grains max for 10 gal mashtun
1.00 qt water/lb grain (2.1 liters/kg) mash thickness = 30.30 lbs grains max for 10 gal mashtun (very thick mash but still get good efficiency)
These US qt/lb to metric l/kg conversions are rounded up or down so they are approximate.
Most "Gatorade style" cylinder coolers actually hold close to 11 gallons so this leaves a bit of room for dead space and put the cover on.
The only downside to squeezing in the maximum grains is you have very little room to add water to adjust your mash temperature if you don't hit close to target with the strike water... Decoction mashing would work (if you are way below) but would require some extra effort and calculating... Not my thing.
