I've purchased a few of the sleeve fillings, and I didn't use the whole thing either time. I put the leftovers in an airtight container and they are sitting on my counter. But I'm wondering if that's okay to do (before I go and use the leftovers). They don't seem to have a brand name, so I don't know where to check. One is strawberry and the other is raspberry. I imagine they're non-dairy, so I didn't refrigerate them, but I'm wondering if I should have. Any advice? How long do they keep??

They're shelf stable, once opened without refrigeration for the short term. For long term storage once onced, refrigerate - they're usually good for about six months. (Just like you would store unopened/opened jam/jelly.)

HTH