Grist: 40% White Wheat Malt, 30% Bohemian Pilsner Malt, 30% Maris Otter.
Brewing Water: Reverse Osmosis H2O with 1 ml of 10% phosphoric acid per gallon to all water used. ½ teaspoonful of calcium chloride and ½ teaspoon of calcium sulfate added to the mash per 5 gallons of finished beer.
Step Mash: 15 minutes at 130° F, 60 minutes at 155° F, then 5 minutes at 168° F. Fly sparge until you reach a pre-boil gravity of 1.051
Boil wort for 15+ minutes, then cool to 95° F and transfer into Lactobacillus fermentation vessel, or leave in kettle if kettle souring. Because we ferment in Sankey kegs, we do not wort at all. We transfer the boiling wort into the stainless steel kegs (with serving tubes removed) and cover the openings with aluminum foil. These are then allowed to slowly cool to 95 F over the next 12 to 24 hours. This completely pasteurizes the fermentation vessels and allows us to use single strain Lactobacillus souring without fear of contamination. As an additional precaution, it is recommended to pre-acidify the wort to pH 4.5 with lactic acid, although we often skip this step because we are confident in the pasteurization of our wort and in our sanitary handling procedures.
Pitch an appropriately sized Lactobacillus culture of your choosing. Hold at the preferred temperature for that strain until you reach your desired pH. For our recipe, we use the probiotic drink Goodbelly, at a rate of 1 carton per 12 gallons of wort, and we allow the wort to acidify to a pH of 3.45 to 3.5, which takes approximately 36 hours.
Transfer wort back to boil kettle or re-fire kettle with souring wort already inside.
After souring, the gravity should be essentially unchanged. Our most recent batch dropped from 1.051 to 1.050.
Boil for 90 minutes. Add US Crystal hops at 30 minutes targeting 8 IBUs.
At end of boil, dilute using R.O. H2O to a starting gravity of 1.035 (this can be done earlier in the boil if contamination is a concern). It is interesting to note that diluting with pure water will not change the pH of your wort.
Cool wort to 65° F, oxygenate, and pitch healthy starter of German Ale / Kolsch yeast at an appropriate cell count. We used a slurry created by pitching 2 White Labs Pure Pitch packs into a 4.5 liter starter.
Ferment at 65° F for 5 to 7 days.
Cold crash to 50° F for 2 days, then keg, carbonate, and enjoy!
The final beer should reach a final gravity of around 1.006 (82.4% attenuation, 3.8% ABV) and have a final pH in the 3.25 to 3.35 range.