I have a RIMS and I am trying to figure out what the correct water to grist ratio should be. Lets say I am using 10lbs. of grain. If the recipe calls for 1qt. per lb., I figure 10 qts. plus an additional 6 quarts to make up the dead space under the false bottom and RIMS plumbing. So, my water to grist ratio would be 1.6 quarts PPPG. Thus, 20 lbs. grain would be (20x1)+6=26qts or1.3qts. PPPG. Am I figuring this correctly? And if so do I use the corrected ratio (in this case 1.6 or 1.3 respectivly) for determining my strike temp?
I am using a grain absorption rate of .13 gallon per lb. of grain. Is this a static amount? And since I am brewing 5-10 gallon batches, do the above rates change enough to require alteration?
Thank you for your help. Pi