Fast Sour Beer

Ingredients

• 2 cups Briess light dry malt extract
• 2.5 pounds 2 row malt
• 2.5 pounds white wheat malt
• 1 liter tap water
• 2 tablespoons yogurt with live and active cultures or liquid probiotic supplement
• 1 ounce fresh herbs, such as rosemary, lemon verbena, and/or lemongrass
• 1 375 milliliter bottle unpasteurized wild ale
• 1 package Brettanomyces Bruxellensis
• Small container of Starsan Sanitizer
• 2 gallons purified water

Directions

1. In a medium saucepan over high heat, bring 1 liter of water to a boil for the starter wort, meaning the unfermented beer. Take the pan off the burner and mix in 2 cups dry malt extract until no dry bits remain. Return the pan to the heat and boil for 10 minutes, then put on the lid and run cool tap water over the pan until the wort reaches 120 degrees F. When it has cooled, add 2 tablespoons Greek yogurt to a sanitized 64-ounce mason jar or glass jug, then pour the cooled wort over it. Set foil loosely over the opening, then wrap the vessel in a blanket or neoprene sleeve for insulation. Keep it as close to 110 degrees as you can for 60 to 72 hours.
2. Warm 1.5 gallons water in a stockpot to about 160 degrees F, then stir in all of the grain, breaking up any clumps as you go. Put the lid on the pan, take it off the heat, and wrap the pot in a thick towel so it stays at temperature for 1 hour. This is your mash tun.
3. While that rests, heat another 1.5 gallons of water in a separate kettle to 170 degrees. This is your hot liquor tank, the hot-water supply you will use later to rinse the grain. Once the hot liquor tank reaches temperature, set the mash tun over medium heat and bring it to 175 degrees, then shut off the heat.
4. Set a large fine mesh strainer over a third 5-gallon brewing kettle; a 12" diameter strainer has just enough room for 5 pounds of grain. Pour everything from the mash tun through the strainer into the kettle. Leave it until the grain has drained completely. Ladle all 1.5 gallons of water from the hot liquor tank over the grain in the colander, washing any remaining sugars from the grain surface. When you are done, taste the grain; it should no longer be sweet. If any sweetness remains, heat more water to 170 degrees and continue rinsing the grain until it tastes bland.
5. At this stage, you should have about 3 gallons of wort in the kettle. Bring it to a boil over high heat, then add the herbs and stir. After 15 minutes, check the steam for any cooked-corn smell, which indicates DiMethyl Sulfide, or DMS. You are aiming to sanitize the wort and drive off DMS while keeping as much volume as possible. If that DMS aroma is still present, continue boiling until you can no longer smell it.
6. When the boil is finished, turn off the heat and put the thermometer into the wort. Add 2 gallons of refrigerated purified water to the kettle, bringing the volume to 5 gallons and lowering the temperature to between 120 to 130 degrees F. If it is still a little warm, stir briskly with a large spoon to help it cool. Once it is in range, pour the entire bacterial starter, liquid and solids, straight into the kettle. Cover the kettle snugly with foil or plastic wrap, wrap it in a thick bath towel, and hold it at temperature for 24 hours so enough acidity can develop. Since fermentation produces heat, this simple insulation should keep it above 100 degrees overnight, which is ideal for lactic acid-producing bacteria.
7. 24 hours later, sanitize the fermentation carboy by adding 1 teaspoon of Starsan sanitizer to a gallon of water inside the carboy. Shake it, then roll the carboy on its side so the sanitizer reaches every interior surface and the opening; pour it out when you are finished. Pour off 10 ounces of the storebought unpasteurized sour beer and reserve it for your well-deserved enjoyment, leaving just over 3 ounces, about the bottom quarter of the bottle, with the yeast- and bacteria-rich dregs. Use an auto-siphon device to move the soured wort into the carboy, then add the remaining liquid and dregs. Fit the top with an airlock and rubber stopper, then place the carboy somewhere cool, in the high 60s to low 70s, to encourage yeast activity more than additional bacterial growth and souring.
8. Begin tasting periodically with your pipette reserved for sour beers, starting at about 2 weeks from the initial brew day. When the beer tastes tart and lightly buttery from diacetyl, add the brettanomyces by pouring the full vial into the carboy.
9. About a week after the brettanomyces goes in, taste again with the pipette. If the buttery note has faded and the beer tastes bright, take a sample using a sanitized hydrometer, testing jar, and pipette. If the specific gravity is at or below 1.010, the beer can be moved to a keg or bottles; if it is higher, let it keep fermenting until it reaches that target. Do not pour tested beer back into the carboy.
10. For carbonation, bring 1 cup of water to a boil, turn off the heat, and stir in 4.5 ounces dextrose, also called corn sugar, until dissolved. Pour the mixture into the carboy through a sanitized funnel and leave it for 10 minutes. Use the auto-siphon to fill bottles, capping and sealing them as you work. You should get approximately 48 12-ounce bottles. Or, transfer the beer to a sanitized keg and carbonate according to the keg carbonation instructions. With natural carbonation, the beer should be ready in 2 to 3 weeks.