My Stored / Recycled Yeast Has Better Attenuation

I am wondering if I should be concerned.

I have been using Wyeast 3787 and recycling/storing dry in freezer on ceramic beads over silica gel. I obviously go thru careful sterilization and sanitation procedures to store them as well as allowing them to dry first before they go into the freezer.

My first batch from the original SmackPak usually ends up with FG of around 1.018 to 1.016. However my recycled yeast ends up with FG of about 1.012 - it is consistently lower than the original batch. The beer tastes perfectly fine (actually, quite good!) but the attenuation is higher than I really want. It seems that some yeast selection has occurred during my storage process. Raising mash temp to about 156F does not seem to make a difference.

Curious to know whether anyone has had similar experiences or their concerns.

I would be hard pressed to attribute it to just the reuse of the yeast (although maybe the hardiest of the yeast survive and the weaker ones don’t make it through the process). Even so, I have had the same experience - my guess is that the slurry may simply attenuate better due to the greater number of cells. I don’t have a hemocytometer to verify.

:cheers: