Low mash pH (4.9) from Annie Johnson's CPL/PU talk at AHA 2017.

Double decoction:
Perform a protein rest at 125F for 15min, then pull off about 1/3 of the thickest mash and place it in a separate pot. Bring the pot up to 158F and hold for 15min, then bring it up to a boil for 10min. Stir often so the grains do not burn, but try to allow some 'browning'. Add the decoction back to the 125F mash, little by little, aiming for a beta rest temperature of 148F. Hold this temperature for 30min while adding back any leftover decoction (if any) as it cools. After this has finished, pull off about another 1/3 of the thickest mash a second time and place it in the separate pot. Bring the pot up to a boil for 10min. Add the second decoction back to the mash, little by little, aiming for an alpha rest temperature of 158F. Hold this temperature for 30min while adding back any leftover decoction (if any) as it cools. Then remove grains and dunk sparge in the other pot. After, add second runnings back to bigger pot with first runnings and bring to a boil.

Got crazy efficiency (95%!) due to fine milling for BIAB, and then the long, multi-step decoction mashing.

Add yeast nutrient to yeast starter.

Ferment at 50º until almost done, then raise slowly to 60º for a D rest for a few days. Then keg and lager in keg for 4-6 weeks, carbonate, and serve.