I've realized we go through a lot of sour cream in my household, and I want to start making probably about a pint or two a week during the summer months.
I've been researching for a few hours, and while I haven't found any reusable sour cream culture, I haven't found any reason I can't reuse sour cream culture. On the same websites selling culture, there's reusable yogurt and cheese culture, so I'm pretty sure it's not just a sales tactic.
I've come across a few articles that state you have to be careful with reusing culture for other fermented milk recipes. It looks like contamination with other bacteria is a concern even with yogurt. Learning that, I may just go ahead and start setting aside my culture for the next batch right off the bat, before any spoon or air contamination can hit the yogurt. I learned from my parents, who reuse from the bottom of the pot when we're getting low.
The only reason I can think of for sour cream being an issue is temperature. I assume that at 75 degrees, a lot of different bacterias can thrive. With yogurt at 110 degrees, maybe it's more of a hostile environment to unwanted bacteria, making it more easily reusable?
If that's the case, I think I can make a jar of sour cream and pour it into an ice cube tray and freeze it to provide myself with culture for a few more batches out of that one.
If there's something special about sour cream culture that it's not reusable at all, why is it special, and can I make my own through some process?