To continue on a recent theme about homebrewing with wild yeast I’ll discuss a recent brew made with a strain of wild saccharomyces yeast. Two common styles of beer brewed with wild yeast are the Saison and Belgian blond ales. Since I recently collaborated with “New to Homebrew” blogger Richard Bolster on a wild yeast saison, I decided to choose a Belgian blond ale for my latest wild yeast brewing adventure. Belgian blond ales are light in color (4-7 SRM), tend to be dry, and are only moderately hopped (15-30 IBUs) producing a refreshingly drinkable beer. Belgian blond ales are typically one of the most subtle Belgian ales and as with most Belgian beers this style gets a great deal of its flavor and aroma from the yeast that it is fermented with. The typical fruity ester (lemon, pear, and grapefruit properties) and phenolic profiles (cloves and pepper) of a Belgian blond could be complemented well by wild yeast since these naturally-occurring critters tend to have a much higher ester and phenol profile than most domesticated yeast strains. In order to completely understand the full impact of the fermentation properties of the wild yeast strain I split my batch in half and pitched a commercial strain (Wyeast 3522, Belgian Ardennes) to compare to my wild yeast strain isolated from a nectarine (South Yeast Labs N3).
One of the most surprising aspects of this wild yeast brewing experiment was the color difference between the two beers, as you can see in the above picture. The beer brewed with the South Yeast Labs wild yeast strain (on the left) was almost rose colored while the commercial yeast beer (right) was golden yellow like a Belgian blond should be. I was not aware that yeast could produce compounds that change the color of beer but after speaking with my friends at South Yeast Labs they consistently see that wild yeast has this effect. As I expected, the wild yeast strain had a more phenolic and estery profile common to a Belgian ale compared to the commercial yeast, which was a bit cleaner.
Happy brewing scientists.