the one thing I skipped out on when I first bought all my all grain stuff was a decent thermometer. I was just using the one that came with my turkey fryer. (Big mistake) Needless to say i just got my new digital one in and calibrated it. turns out my old thermometer was off by all most 20 degrees. No wonder my last batch had such bad efficiency. So instead of being at 153 like i thought I was mashing at 140 or lower. Im surprised I got any type of conversion.