The Yeast Aroma Spider Wheel, A new way to look at aroma profiles on

When we first started propagating yeast in Fernbach flasks using a incubator shaker for experimental small-batch brewing purposes, we noticed that each different strain smelled differently than one another. After 48 hours of vigorous aerobic growth, each flask was uncovered, and different members of my lab and certified beer judges were asked to explain the smells in each flask. Even though beer is not made in this manner, the aromas were amplified, and after brewing with the yeast, the smells were less prevalent, but still were detectable in the beer (no hops were included). There was no way to explain the aroma notes in a succinct manner. Hazy IPA strains are an example. RBY87 London Haze smells differently and less fruity over RBY60 Conan Yeast used in the cult beer Heady Topper. In contrast, RBY85 American Haze which was bred in our lab, has a more neutral slightly apple note. Our goal is to use the Yeast Aroma Spider Wheels to help brewer’s choose between stains, although results may differ somewhat in finished and hopped beer. These are delicious strains. Here is few things to consider:


  1. All beer, wine and yeast Saccharomyces strains have a prominent apple note when grown shaken and aerated. This does not mean your beer will taste like apples. It just means that there is an apple note in there that may or may not be covered up with hops.
  2. Variations in gravity, temperature, sugars, pitching rate and aeration will change the aroma profile.
  3. Spider Wheels are a great way to visually describe yeast  aroma.