Lactic acid bacteria (LAB) have many practical uses in the production of sour beers. Although souring beer is a method of “controlled spoilage” – just like yeast, bacteria require specific parameters to perform optimally. Therefore, getting to know your specific lacto strain is critical!

Additionally, there are various brewing methods available to produce sour beers depending on your needs. So, not only do you need to know your bacteria, you also need to have some well established parameters for your brew. For instance, what are your goals? Speed? Sourness? Complexity? Tradition? Low contamination risk? These details will serve as your guide to the methods you use.

Whatever your goal and brewing methodology you choose, your end product will be in good company. You see, sour beers were a dying style saved by American Craft Brewers just like you. In fact, recent history has shown an explosion in sour styles! – 2002 GABF (First Sour Category): 15 entries – 2010 GABF: 149 entries – 2015 GABF: 497 entries – 2018 GABF: 820 entries…and the trend continues to soar.

Now, let’s look at a few details about the microorganisms responsible for souring beers.

There are over 100 species and subspecies of LAB, although the genus Lactobacillus represents the largest group. All LAB produce lactic acid as a product of fermentation. That’s why LAB are used extensively in the food industry for things like food preservation, starters for dairy products (cheese and yogurt), fermented vegetables and meats (sauerkraut), probiotics (L. casei and L. paracasei), and as inoculant for silage/cattle feed (L. acidophilus).

So, although LAB are generally considered a contaminant when present in food processes not requiring fermentation, they are conversely essential in the process of many fermented foods and bio-products. That’s why using LAB in the food process can be thought of as a “controlled spoilage” – carefully monitoring parameters to produce desired results.

Download this highly informative, free PPT presentation entitled Getting to Know Your Lacto. This educational resource developed by BSI Technical Support Specialists is sure to get you on the fast track to brewing optimal sour beers. Cheers! BSI Lacto Presentation 2019