I just mixed the correct amounts and ingredients for a two and a half gallon water mixture of Krowtan, with proper amounts of Krowtan 2000 and salt, when stirring, the mixture began to form a brown scum on the surface of the liquid within the clean plastic bucket I mixed in, and within minutes, this brown "scum" turned into almost an "oily" thick film upon the surface of the solution. The Krowtan was purchased last September, from McKenzie, a new bottle just opened today, and I noticed, also, that the Krowtan has turned dark brown within the shipping container, and has dark brown flakes and flecks within the acid itself. Does anyone know if this is normal, is the material too old, at five months to utilize, do you scoop off this "scum" and continue, or discard this container? I'm new to Krowtan, and wanted to try it for myself, having heard good results are obtainable, but, I don't think any of us would drop their prized fox hides into this concoction, as is! Any ideas? Thanks!