Hi Andy,
Thanks for emailing me about this. I thought I would reply here instead so maybe others could learn along with me.

I did a quick search and read several pages on the subject, but still have questions. Doesn't the glycerin cause problems with the beer? I assume some of it stays with the yeast after being unfrozen and placed in a starter. Sure the starter would be decanted, but some of the glycerin would surely remain. I didn't see any reference to washing the glycerin off the yeast.

While reading up on the use of glycerin and having my mind drifting onto the subject of olive oil, I started to wonder if you could substitute olive oil? I'm sure with a bit more reading on my part, I could answer that question.

Mich Dave

Here is a nice presentation from last years National Homebrewers Conference in Denver

Freeze Your Yeast