Yeast Viability and Vitality

What are Escarpment Labs' standards for viability and vitality? 

Our yeast cultures are checked for viability at the time they are harvested from the propagator. We use erythrosin B to stain dead cells and target >95% viability as a specification. 

We currently measure vitality by monitoring a small-scale fermentation of every batch of yeast. This means that over time we have amassed thousands of data points on our yeast fermentation performance.