I'm going to do revvy's pumpkin partigyle brew in a few weeks. I've read a lot of the threads here as well as mosher's byo article. I'm trying to run numbers in my brewing spreadsheets to prep my recipes and not getting my expected gravities.
For example, I'd like to do 2 2.5 gallon batches, one with OG 1.081 and other with 1.050 or so. I understand that my "master recipe" will be made as about 1.066 at 5 gallon. Mosher says to expect 60% of points in first runnings and 40% in second. When I run equal sparge volumes (ie: drain equal volumes of 1st and 2nd runnings) in my software, I get gravities of 1.091 and 1.032.
I know that I can easily mix a bit of each running together on brew day to hit my gravities, but I'm a science/math guy and like when I can get things to make sense to me. Is it just that partigyle numbers don't necessarily work right in my brewing calculators? Or an I missing something else? I've also run numbers on the two individual batches with 60/40 split and find i need more grain than expected to hit 1.050 for second runnings. (not sure if I'm getting my question across through this post...I'm thinking about just running with revvy's numbers and hoping for the best and correct gravities as I go on brew day)