I'm well aware, originally the issue or concern was I restocked my campden and the newer tablets caused a film on the surface as well as not dissolving. Haven't been able to discover from the supplier any details as I believe they resources their supplier from a cheaper source. I've done side by side comparisons and have tossed the "bad" campden. Might be nothing wrong with them but I don't like what they are doing, not tossing the mead as I want to let it go all the way to bottling to see if anything does happen down the road.