A good question but it was not a new batch of chemicals. I actually glazed 4 or 5 pieces with the new 20,000 gram bucket and they came out perfect. I went back to glazing several days later and the glaze was hard-panned. That is when I added the bentonite and epsom salts.
Next firing in a month or so, I will pour out half of the bucket into a a separate bucket and add the Mason Stain #6600 and see how it turns out.