So I heard back from CK Products today right after I issued my followup email, and they said they've changed to a finer sugar, so all is better now (see email below). In addition to taking them up on the offer of a sample (to test for myself before I buy again), I also asked for the starting lot number with this change, as I want to avoid old lots that may be troublesome. I'll keep you posted if/when I learn more.