I just finished up my 3rd AG batch, Ed's Kolsch recipe. My first two attempts created good beer, but my efficiency was horrible, around 58%.
This time around I tried 5.2 stabilizer and watched my temps a little more closely. Turns out the thermometer I was using before had a loose wire in the probe and wasn't reading an accurate temperature. It must have been coming loose for awhile and got really bad today. I put it in hot water and it read -6. I figured something wasn't right.
I also found out that my cooler mlt sucks up a ton of heat initially, I lost over 15 degrees while it heated the tun. But, I was able to hit my temp and mash at 151 for the full 60 minutes. What surprised me was that I added 185 degree water to sparge and the grain bed only ended up at 160. Is this normal, or do I need to sparge with hotter water?
It was all good in the end though, I ended up with 5 gallons and the SG was 1.053, which I believe is about 75% efficiency. I changed a lot this go around, so I'm not sure what added to my increase the most. The 5.2 stabilizer, watching the temps better, or maybe the crush from Brewmasters Warehouse is better than the crush at AHS. Whatever it is, I'm glad I finally got good efficiency, makes me feel much better about brewing AG.