This month, citizens, we’re going to revisit our kettle-souring regimen for a beer inspired by Florida weisse—a riff on Berliner weisse that nontraditionally incorporates fruit (specifically local/tropical types like guava, passionfruit, and dragon fruit) right in the fermentation, rather than added as a syrup in the glass when served.
Making use of our local malts, hops, and fruit, it’s time to give the world a Minnesota Weisse.
Target OG: 1.040, Target IBU: <10
- 3½ pounds Rahr Premium Pilsner
- 3½ pounds Rahr White Wheat
- ½ ounce your choice fruity/floral aroma hop variety—homegrown, Minnesota-grown, or substitute
Yeast & bacteria
- Wyeast 5335 Lactobacillus, propagated in starter (see key points, below)
- Safale US-05, or your choice of neutral ale strain
- Your choice of local/native fruit (see key points, below)
Key points for key pints
• Lacto starter. Kettle-souring requires a big dose of bacteria, so we’ll propagate a pack of Lactobacillus ahead of time. On brew day, mash and sparge as normal, followed by a cursory boil to sterilize, then cool. Pitch Lacto and ferment in the boil kettle, keep it warm for a couple days, then boil again, add hops, and so on.
• Hop choices. Locally grown or homegrown hops are in keeping with the ethos of this month’s recipe; if you have Cascade, Centennial, or anything from the Hallertau family growing in your yard, this would be a good place to use them. Vic Secret, Galaxy, Callista, or Wai-iti are decidedly non-local but would be really nice for this beer.
• Fruit choices. The sky (and/or your farmers market or co-op) is the limit. Depending on the flavor intensity of the chosen fruit, we’ll need somewhere between 0.5–2 pounds per gallon. Here are some suggestions:
- Blackcurrants (3–5 pounds per 5 gallons)
- Blueberries (10 pounds per 5 gallons)
- Raspberries (8–10 pounds per 5 gallons)
To the homebrewery
Note: These steps are general guidelines and assume you’re already familiar with the all-grain brewing process. Refer to the instructions for your brew system and adjust as needed based on experience with your own particular equipment.
Prep: 1–2 days before brew day
1. Prepare a Lactobacillus starter using 1 liter of water and 4 ounces plain light DME. Cool to approximately 100°F and inoculate with the 5335 Lactobacillus. Incubate at a very warm temperature (85–100°F) without stirring or agitation.
2. Clean the fruit well, discarding any bruised or rotten pieces. Place the cleaned fruit in a freezer-safe bag, then put in the freezer until brew day.
Prep: On brew day
1. On brew day, collect strike water, and heat to approximately 163°F.
2. Mill the grains, or have it done for you at the shop.
Mash & sparge
1. Add all grains to strike water and mix to achieve a uniform temperature of 150–152°F. Rest the mash at this temperature for 60–90 minutes.
While the mash rests, collect, and heat sparge water.
2. When the mash rest is complete, heat it to 170°F for mashout.
3. Sparge and collect the wort in the boil kettle.
1. Use a boil kettle that has a well-fitted lid. Bring the wort to a boil for a couple minutes to sterilize, then allow to cool—you can use an immersion chiller if you like, or just let it cool passively with ambient temps (don’t worry about DMS formation at this point—the wort will be boiled again). Keep the wort in the kettle—no need to transfer, the lactic fermentation will take place right in the boil kettle.
2. Once the wort temp is below 120°F, inoculate with the entire Lacto starter and cover the kettle with the lid. (If you want to go all-out, flush the headspace of the kettle with CO2).
3. Allow Lactobacillus to ferment 1–3 days. Do not oxygenate or aerate, and maintain a fermentation temp of 80°F or above. All other things equal, the bacteria will work faster at warmer temps, up to about 120°F, in an anaerobic environment.
4. Once the wort has soured to your liking (a simple sensory evaluation of the sour wort will be enough), proceed to the main boil.
1. Bring the soured wort back to a boil and think how nice it is to live in a state with no alligators. Add 0.5 ounces of your selected hops at the end of the boil, and steep for 20 minutes or so prior to chilling.
2. Cool it!
Fermentation and beyond
1. Remove the frozen fruit from the freezer and dump into an empty, sanitized wide-mouthed fermenting vessel (at least 6 gallons—bigger may be better, depending on how much fruit you’re using).
2. Transfer the cooled wort onto the fruit in the sanitized fermenter, aerate well, and pitch yeast.
3. Depending on the yeast strain being used, aim for a maximum fermentation temp in the low to mid 60s°F.
4. When gravity is stable and the beer is sufficiently clear (the fruit will contribute some amount of haze), siphon off the fruit, and proceed with packaging.
5. Don’t delay gratification—enjoy immediately.
Until next time: Drink it like you brewed it.