Have you ever seen or purchased, sour cream, or buttermilk starter?

Just wondering where I'd find some?

Haven't seen that. I made some sour cream the first time I made yogurt. The milk was nearing the starting to sour state. I figured I would practice with it. It made a great sour cream substitute! I used it for ranch dip and taco dip (taco mix in the sour cream). I have buttermilk powder but I don't think that's what you are talking about.

Carol,
Theres a couple of recipes in this issue of Backwoods Home, about making cheese, sour cream, yoghurt, buttermilk, ect. They mention the starter that you can buy in packets. Ive never seen it anywhere & didnt even know there was such a thing. May have to hunt some down online.