How do I tell if my cheese culture is still good? I made cream cheese in November and prepared some of my own starter culture from that batch to save money down the line when I wanted to make cheese again. Well, I haven't made cheese since then (now about 4 months later) and I don't know if my starter is still good.

I kept the starter in the freezer since November in ice cubes, and I kept my environment pretty sterile when I made it.

How can I test it to see if it's still good?
I think that your culture should be fine, given your storage method and sterility in handling. All you can really do is try making some cheese, and see how it turns out.