Originally Posted by SavoryChef
I don't own a 20 gallon Blichman so that's why I'm asking.
The water to grain ratio matters if there is 2 gallons of space under the false bottom when doughing in at 1.25 qts with 8.5 # of grain.
I have both a 10 and a 20 gal Boilermaker that i use then for 5 and 10 gal batches, respectively. They both work great. There are several reasons not to use a 20 gal Blichmann for a 5 gal batch:
The larger surface area will make the grain bed very thin with little filtering ability.
The large volume of the pot in relation to the amount of water and grain makes maintaining temps more difficult.
The Brewmometer will be to high above the mash to be useful.