I brewed with 18 month old Rahr 2-row. My process has been dialed in for several years. Missed my OG by .003. feeling like Tom Dooley. Estimated 1.056 OG, Measured 1.053 OG. I have got around 175lbs of malt climbing past 18 months. A .003 miss is HUGE for me so I need to make a correction to the potential yield of the bird seed or malt to get the results where they need to be so I can crow I hit my numbers. Let me know if my plan is OK. The potential yield originally of the base malt was 1.037. I went back into the original recipe and decreased the PY of the Rahr base malt in small increments until the estimated OG was the same as the actual measured OG which resulted in PY 1.0345. Can I assume moving forward this is an as accurate as a guess-estimation to enter to use for a new potential yield for the 2-row grain? Plugging the numbers into a copy of the recipe told me I was 1.5 lbs. under with the base malt.