So I've got 7 batches under my belt, which is enough to notice some pretty consistent trouble areas in my process. I figured I'd ask the questions and attempt to answer them myself. Any feedback would be greatly appreciated. I assume some brewers might be having similar questions and benefit from this too. I realize there's a lot here, but I've been saving my questions to avoid flooding the forum with panicked "help" posts.
1. Fluctuating mash temperature
I add the crushed grains to the strike water in my pre-heated mashtun (I use boiling water) and stir. I use Palmer's formula to calculate strike temp (.2/mash thickness)*(t2-grain temp)+t2 and always seem end up with too hot a mash, anywhere from 5-10 degrees. I add ice to cool it to temp and put the lid on. However, when I check 15 minutes later, the temperature has usually dropped 5-10 degrees into the 140s. I add boiling water and then usually it's stable at the temperature I want it. This means I usually spend about 15 minutes at 160, 15 minutes at 145, and 30 minutes at my desired temp.
---Pre-heat my mashtun with slightly overheated strike water instead of boiling water in case my tun is adding heat to my mash.
---Give a chance for the grain to absorb all the heat from the strike water. Put the lid on for a good 5-10 minutes immediately after stirring and only then check the temperature to add ice. I think I might be reacting to a high mash temp before things have even stabilized.
---Mash a little thinner. Since I'm doing half batches in a 5 gallon converted cooler and usually making low gravity english beers in the 1.040 range, there is quite a bit of head space. The temperature might stay more constant with more mash and less head space.
2. Mash pH
I have extremely soft water but also enjoy darker beers. (Alkalinity in the 30s, with all minerals except calcium below 10 ppm.)
---Add minerals, especially calcium carbonate, in order to get things in the healthy range for most ales.
---Add the 5.2 product to the mash.
UPDATE: I've done both of these things with the past two batches. Based on the higher attenuation I'm seeing, I think it has improved enzyme activity overall. My efficiency has improved nearly 20% for darker ales (85 from 65). Will adding 5.2 mess up any special water profile I've created?
3. Batch sparging
I got the highest efficiency my first time when I basically did a half dozen sparges and the worst when I did a manual fly sparge (ladeling in sparge water over the grain bed as it drained). I've gotten a consistent 85% with this process: Collect the first runnings after doing my mashout. Then add enough water to cover the grain bed by an inch or two and collect these second runnings while doing a manual fly sparge until I've hit my pre-boil volume. The concern is that I've noticed some tannins, especially in my darker ales done this way.
---Measure out the sparge water for the second runnings and do a normal batch sparge rather than manually fly sparging and watching the kettle volume. Since my manual fly sparge isn't as consistent as it would be with a sparge arm, I might be getting some unpredictable channeling and low gravity runnings.
So that's it. If anyone made it this far I'd be both very impressed and very grateful.