My yeast has arrived inflated, is it okay to use?

Yes, it’s fine to use.

Trace levels of fermentable carbohydrates or CO2 in yeast slurries at the time of packaging can cause a slight expansion in packs. “Off gassing” is a result of a small amount of metabolism or simply CO2 being released from the media and can occur even during proper storage. This does not indicate the mishandling of the yeast or a decline in the health or purity of the culture. Some strains of yeast are more prone to “off gassing” than others.

What if you don’t wish to use the yeast immediately?

If you have activated a package but can’t use it right away, simply allow the package to swell and then refrigerate the package. The yeast will survive for extended periods if refrigerated. Before using, take the package out of the refrigerator and allow it to come up to room temperature before using. It is best to use the yeast as soon as possible.