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Fun with wild yeast and bacteria

Editorís note: In the last issue of Craft Beer Quarterly, Chris White outlined White Labsí new bacteria/other yeast program. In the following article, guest writer Tomme Arthur, brewer at Pizza Port in Solana Beach, discusses his experience with wild yeast and bacteria. 

By Tomme Arthur

I canít remember when I first got interested in bugs ... the thing is, I detest insects with lots of furry legs. However, that being said I am enamored with the creepy crawly critters in the brewing world ó those nasty beasts known as wild yeast and bacteria. To me, these buggers make some of the most fascinating flavored beverages and create depths of interest not seen in pure yeast cultured beers.

I am quite certain that my first commercial encounter with these critters was a bottle of Orval. At the time, I had only read of "wild yeasts" and knew very little about their role in brewing. My notion of wild yeasts was exclusive in such a way that we as brewers strove not to include them in our beers. This comes from a scientific brewing heritage where brewers are taught about the big three and I am not referencing the largest brewing companies in this country.

The big three I am referring to are Brettanomyces, Pediococcus and Lactobacillus, all of which are considered to be beer spoiling micro-organisms. Each of them is uniquely capable of tainting beers with flavors most brewers consider highly undesirable.

At the Pizza Port in Solana Beach where I am employed, we are consistently stretching the proverbial limits of our creativity and have come to realize that many of our wildest imaginations can only be achieved through the use of such critters. These animals are harbored in our own private zoo consisting of tanks and barrels that contain our brewing bugs. Some of our more interesting beers are made in these oak barrels we have inoculated.

One such beer that we created is our infamous and somewhat elusive Cuvee de Tomme. This beer has been called Rodenbach on steroids but we have yet to find any vials or jars of "The Clear" in our brewery. The beer is modeled after the Sour Red and Brown ales of Flanders. In order to achieve many of the flavors associated with these beers, we began inoculating a base beer with three separate strains of Brettanomyces.

We initially started working with Brettanomyces because of the three beer spoiling micro-organisms, it is the easiest to grow and maintain. It is classified as a wild yeast and as such, it has similar requirements and nutrient makeups like that of traditional saccromyces brewing strains. With this in mind, we have been able to keep and maintain our own strains of Brettanomyces in the brewery with very little effort. We are currently maintaining three separate strains of Brettanomyces for our brewery in Cornelius Kegs. Other breweries including Russian River in Santa Rosa, Calif., are keeping multiple house cultures of Brettanomyces going in glass carboys. Maintaining the strains means using them on a regular basis and propagating with fresh wort when more yeast is needed. In this way, a consistent pitching quantity will always be on hand.

Since Brettanomyces is a wild yeast, there are numerous examples available with each offering different flavor possibilities. The three most common strains of Brettanomyces found in beer are Brettanomyces Bruxellensis, Brettanomyces Lambicus and Brettanomyces Anomolus. The most common flavor associated with each of these yeasts is the proverbial horse blanket and sweaty flavors found in "nature."

Brett Bruxellensis has been isolated from beers in both the lambic world as well as more classically the culture that is used in the secondary fermentation of Orval. This robust Trappist ale is the most unique Trappist Ale produced in Belgium with its use of Brettanomyces for a secondary fermentation. This strain of Brett is quite dominant and produces a "cleaner" brett aroma than other Brett strains.

Brett Lambicus has been isolated from the Lambic Producing region of Belgium. It has a more robust character then the Bruxellensis and is responsible for much of the super attenuation that occurs in Lambic and Sour Ales of Belgium. This strain produces the funkiest aromas with heavy Brett notes of sweat and classic "barnyard" esters. This one is not for the faint of heart.

Brett Anomolus has also been isolated from Belgian Brewing Cultures as well as some of the Stout Cultures from Irish Breweries. It is in this sense sometimes referred to as the "Stout Strain" of Brett. It produces an ester that is more mild and somewhat less "horsey" than Bruxellensis and Lambicus.

In April of 2004 we conducted an experiment at Pizza Port in Solana Beach and brewed Moe Betta Bretta, a 100% Brettanomyces Anomolus Fermentation. This collaborative beer developed and brewed with Peter Bouckaert of New Belgium Brewing Co. tested the potential for 100% Brettanomyces Anomolus fermentations. The finished product was quite aromatic with notes of pineapple and passion fruit. A much more reserved quality of barnyard esters was perceived due to the Anomolus fermentation. Bouyed by our success, Vinnie Cilurzo of Russian River Brewing Co. in Santa Rosa created Sanctification ó a 100% Brettanomyces fermented ale made with a blend of Brett Lambicus and Bruxellensis. The beer is now part of the Russian River line of bottle conditioned products with an impending release of what has previously been a draft only product.

The possibilities of brewing with Brettanomyces in the future are quite numerous. Further to the East, both Southampton Publick House and Mackenzies Brewhouse continue to brew Belgian Style Pale Ales with secondary fermentations yielding beers with similar hop and Brettanomyces qualities similar to the ones in Orval.

Whether it is a primary or secondary fermentation with Brettanomyces, the use of wild yeasts to create interesting and in the case of our Cuvee, signature aromatic and flavor profiles is something that more and more courageous brewers are engaging in. White Labs will be working very closely with brewers in the coming months as new Brett strains are released and brewers are given yet another tool in their proverbial arsenal of agents whose job it is to seek and destroy malt based sugars.

If you have your own brewing experiences to share, write For more information on White Labsí bacteria/other yeast program, click here.

Chris White and Tomme Arthur presented a discussion called "Brettanomyces Yeast in Beer" at the Craft Brewers Conference in Philadelphia on Saturday, April 16, 2005. More information from the talk will be posted on this Web site in the near future.