Jester King Craft Brewery

Pellicle Photos

Here are a few photos we took of pellicles on our beer. These pellicles have formed over the surface of beer aging in oak barrels in our barrel room. A pellicle is a thin, protective layer of organic matter that covers the surface of the beer. It’s created by yeast in order to protect the beer from oxygen. Wild fermentation requires a little oxygen, but not a lot. Without a pellicle protecting the beer as it ages and slowly ferments, the risk of oxygen contributing to the growth of acetobacter becomes a concern. Acetobacter, while harmless, produces volatile, vinegary flavor in beer. We go to great lengths at our brewery (mainly by temperature controlling all of our wild fermentations) to keep acetic acid in our beer to an absolute minimum.

Anyhow, despite the amateur nature of these photos, they still give a sense of what a few pellicles on our beer look like.