Corey Blodgett’s #KölschStyle

Mill the grains and mash at 135°F (57°C) for 15 minutes; raise to 145°F (63°C) and rest 45 minutes; then raise to 162°F (72°C) and rest 10 minutes. Recirculate until the runnings are clear, then run off into the kettle. Sparge with 172°F (78°C) water, topping up as necessary to get about 6 gallons (23 liters) of wort, depending on your evaporation rate. Boil for 60 minutes, adding hops according to the schedule. After the boil, chill to about 58°F (14°C), aerate the wort, and pitch the yeast. Ferment at 60°F (16°C). After fermentation is 75 percent complete (about 1.018), allow rise to 68°F (20°C) for a diacetyl rest. If you can, cap the tank with a spunding valve when the gravity is at about 1.013 (or when there is about 1°P left to ferment). Crash to 34°F (1°C) and lager for 3 weeks or more. When ready to package, aim for 2.4–2.5 volumes of CO2.

BREWER’S NOTES
Water profile: My water in Milwaukee has 96 ppm calcium, 47 ppm magnesium, 26 ppm sulfates, 7 ppm sodium, 16 ppm chlorides, and 107 ppm bicarbonates. Aim to get the bicarbonates (HCO3) somewhere between 150–225 ppm. This is where Kölsch and altbier get their snap.

Mash: If you’re doing single-infusion, mash in at 148–149°F (64–65°C). Aim for 1.7 qt/lb in your mash (about 14 quarts or 13 liters for a 5-gallon/19-liter batch). Rest 60 minutes, then follow the remaining directions above.