Sour beers have become a significant part of the craft beer community. The style has passionate fans, entire breweries dedicated to their creation, and even a sub-style in the 2021 BJCP Guidelines (Style 28D. Straight Sour Beer). But for many homebrewers, the usual process of souring beer can be intimidating, maybe even a little frightening, given its “infectious” nature.

Lallemand and the University of Sciences have come to the rescue for brewers hesitant to enter the world of sours!

Summer of 2020, Lallemand introduced a new product in their “Wildbrew” line. The product is called “Philly Sour,” a new yeast. But not your typical yeast. As the name suggests, “Philly Sour” is a lactic acid-producing yeast. It does both tasks typically associated with creating a sour beer – it both sours and ferments on its own with no need for a second souring process or introducing any bacteria.

The University of Sciences in Philadelphia, PA, discovered, isolated, and cultivated this unique yeast strain. As part of Dr. Matthew Farber’s Brewing Sciences Certificate program, students set out on a “yeast hunt,” collecting and studying wild yeast strains from the surrounding areas. On one “hunt” in the Woodland Cemetery park area across from the university, strain GY7-b was collected from the bark of a dogwood tree. This strain was the proverbial “needle in a haystack” of yeast strain discoveries.

After many tests and analyses, this yeast strain was found to create lactic acid during its first fermentation phase and then produce ethanol as expected from all brewing yeasts. The lactic is made during the first 4 to 5 days of primary fermentation, and the total fermentation time typically lasts ten days. It ferments within an ale strain temperature range between 68 and 77 degrees Fahrenheit. And in case you somehow missed it earlier in this article, this single yeast is all you need to create sour beer – no need for bacteria, no lactic acid additions – one yeast, one fermentation, one unique outcome.

Philly Sour is an excellent choice for classic sour styles like Saisons, Fruited Sours, Gose, and Berliner Weisse. It’s also an excellent choice for just about style or experimental brew you want to try to sour. With it being a yeast used in a 1 step souring and fermenting process, there is virtually no limit to the creativity that can be applied using this yeast—looking for an example? Our club Secretary Matt Hunsworth has recently tested it, making a Grape Juice flavored sour. You can see the entire process and results online here:

Interested in trying Philly Sour but now sure where to start? Here’s a simple recipe that creates a clean, simple sour beer that also makes an excellent base to add juices, syrups, etc., to experiment with and brainstorm some ideas:

SUPER SIMPLE SOUR recipe:

5 lb Pilsner Malt
4 lb White Wheat Malt
8 oz Rice Hulls 

Mash at 150 degrees F for 60 mins 

Boil for 60 mins. 

Add .5 oz of Tettnang Hop pellets at the last 10 mins of the boil. 

Chill the wort to 68 degrees F 

Pitch two 11g packets of Lellemand Philly Sour yeast (re-hydrated suggested). 

Philly Sour is available from our longtime sponsor, Hearts Homebrew. You can pick some up in the store at 6190 Edgewater Dr, Orlando, FL, or order it online here. 

Eager to learn more about Philly Sour? Check out these great presentations from Lellemand with Dr. Matthew Farber: