Hey everyone, I am going to try a parti-gyle brew this weekend. I understand the whole process (first runnings the big beer with 1/2 the sugars, 1/3 the total wort, second runnings the small beer, 1/2 the sugars, 2/3 the total wort, etc.) I plan on brewing an Imperial Stout/Dry Stout combo.
I'd like to yield 5 gallons big beer (1.09 OG), 10 gallons small beer (1.045 OG). based on some equations from Randy Mosher http://www.brewingtechniques.com/library/backissues/issue2.2/mosher.html It looks like I need an entire batch gravity of around 1.060. So here's the question: does that mean I have to buy enough grains for a 15 gallon batch at 1.060? How does this 1.060 gravity apply to amount of grains to be purchased? How many pounds of grains are needed for this brew?!
I've been batch sparging, getting around 70% efficiency on my equipment.