Submission from Lallemand

The innovation.

Sour beer, known for its distinct flavour, is a broad category with various substyles that focus on the drinker’s perception of acidity, primarily due to lactic acid. In recent years, sour beer has seen a surge in popularity, making it one of the fastest-growing segments in the craft beer industry. Conventional sour beer production method includes souring of the mash or wort using lactic acid bacteria, followed by alcoholic fermentation using yeast. Although traditionally used, this two-stage process is cumbersome and tedious for brewers, and requires handling of bacteria, which often introduces contamination risk(s) in the brewery. 

To address these challenges, Lallemand has developed an innovative solution: a genetically engineered yeast strain that simplifies the process by simultaneously producing lactic acid and ethanol. This yeast, derived from the conventional LalBrew Nottingham® brewing strain, enhanced with lactate dehydrogenase from Rhizopus oryzae, is marketed under the brand name Sourvisiae®. The resulting Saccharomyces strain (Sourvisiae®) offers brewers a more efficient and controllable method to achieve the desired sour flavour levels, resulting in faster fermentations and improved consistency in products.

The benefits.

Sourvisiae® allows the brewer to ferment and sour the beer in one simple step, reducing cross-contamination risks, lowering costs and cutting total process time. The brewing process is conducted without any modifications; Sourvisiae® is pitched just like conventional yeast and ferments within the usual timeframe. Unlike other souring methods that can introduce additional flavour compounds from the likes of species from Brettanomyces, Lachancea, or lactic acid bacteria, Sourvisiae® ensures clean, consistent and reproducible sourness in the beer. Furthermore, Sourvisiae® is safe, non-hazardous and is Generally Recognized as Safe (GRAS) in the United States.

Additional materials:

LalBrew Sourvisiae Lactic-Producing Yeast