Brewing Sour Beer: A Kettle Souring Recipe

Brewing Sour Beer: A Kettle Souring Recipe

Brewing sour beer is a rewarding but time-intensive process that allows you to create delightful tart flavors. In this recipe, we’ll guide you through the kettle souring method, which is a popular approach for making sour beer at home.


  • 5 gallons (19 liters) of wort: Prepare a simple malted barley wort by boiling and cooling it. Make sure it’s free of hops.
  • Lactobacillus culture: You can obtain this from a commercial yeast supplier or use a small amount of unflavored yogurt as a source of lactobacillus.
  • Kettle or brew pot with a lid: To sour the wort.
  • Fermentation vessel: A glass carboy or food-grade plastic bucket with an airlock.
  • Brewer’s yeast: Select a yeast strain suitable for the beer style you want to create.
  • Sanitization equipment: Ensure everything is thoroughly sanitized to prevent contamination.


  1. Prepare the Wort: Boil your wort as you would for a regular beer, but without any hops. Once the wort has cooled to around 120°F (49°C), transfer it to the kettle.

  2. Pitch Lactobacillus: Add the lactobacillus culture to the wort. Ensure the kettle is sealed tightly to prevent oxygen from entering.

  3. Incubate: Keep the kettle at a temperature of around 110°F to 120°F (43°C to 49°C). This is the optimal range for lactobacillus fermentation. Allow it to sour for 12 to 48 hours, depending on your desired level of tartness. Taste the wort periodically to monitor the sourness.

  4. Boil: Once the desired sourness is achieved, bring the wort back to a boil to kill the lactobacillus. This step will halt the souring process.

  5. Add Hops: If your sour beer style requires hops, add them at this stage and boil for the recommended time.

  6. Cool and Transfer: Cool the wort and transfer it to your fermentation vessel, leaving enough space for fermentation. Pitch your brewer’s yeast.

  7. Fermentation: Seal the fermentation vessel with an airlock and allow the beer to ferment according to the yeast’s instructions. This can take a few weeks to several months, depending on the style.

  8. Bottle and Age: Once fermentation is complete, bottle your sour beer with priming sugar for carbonation. Age the bottled beer for several months to allow flavors to develop.

  9. Enjoy: Chill and enjoy your homemade sour beer! The flavors will continue to evolve over time.

Remember that sour beer brewing requires careful sanitation to prevent unwanted bacteria and yeast from contaminating your brew. Experiment with different lactobacillus cultures and yeast strains to create unique sour beer variations.