Omega Yeast’s Guide to Kettle Souring

Sour beers have found their place on the tap list, though their dry acidity is likable to wine or certain cocktails. Most sours are fermented one of two ways: 1) quick turnaround or "kettle sours" use Lactobacillus, typically before the yeast is pitched, resulting in a clean lactic tang (a good way to produce refreshing Berliner Weisse-style beers that can also contain fruit), or 2) Lactobacillus and/or Pediococcus acts during a long secondary fermentation, often in conjunction with Brettanomyces, resulting in a dry acidity akin to wine (think Belgian Lambic). Brewing sour beers can take a bit of skill, but you’ll be well on your way with our Lactobacillus Blend (OYL-605).  

Check out our tutorial below, and please reach out if we can help -

Using a direct pitch?

(We recommend a pitch rate of 1L per 3bbl of unhopped wort.)

  1. Simply prepare your wort as normal (but without hops!)
  2. Boil briefly
  3. Chill wort to 100ºF or below
  4. Pitch Lacto

Most brewers reach their desired pH in under 24 hours. 

Using a starter?

(A five gallon starter is appropriate for quickly souring up to 50bbl of wort.  For larger batches, increase starter size.)

  1. 24 hours before brew day:
    a.  Pitch 1L of Lacto into ~5 gallons of unhoped, 7-10P wort
    b.  Allow the Lacto to grow anywhere from 70ºF-100ºF.
  2. On brew day:
    a.  Simply prepare your wort as normal (but without hops!)
    b.  Boil briefly
    c.  Chill wort to 100ºF or below
    d.  Pitch Lacto

Most brewers reach their desired pH in under 24 hours.  

Looking for more?

Omega Yeast’s own Adi Hastings was featured on the Milk the Funk Podcast – where he goes in depth on the kettle souring process, including microbes, techniques, and tips on avoiding off-flavors. They also discuss the possibilities of using this method for making beer styles other than Berliner Weisse and gose, as well as industry issues surrounding this process. Check it out!