I've been making bath bombs for five years and have never had this problem. I'm so frustrated, so I hope someone can help! Two batches have done this... Everything's going fine 'til about a week plus after the bombs are packaged. I find that they are puffy with white patches and I assume they've fizzed a bit 'cause they don't fizz very much at all in the bath. I'm sure the packaging is air-tight, 'cause I haven't changed my packaging either (cello bags tied with paper raffia). So, I'm totally at a loss. I did read somewhere that epsom salts make be problematic. I added them semi-recently. I used to only use salt with the baking soda and citric acid. I'll go back to that. But, I don't feel like ruining another batch 'til I have a better idea of what went wrong. Also, just to note: I use either cocoa butter or mango butter to hold my bombs together. I don't use water or alcohol or witch hazel to get them to hold together. I've always done it that way. I would assume that humidity was a factor. However, like I said, I haven't come across this in five years, and the bombs are packaged. Any ideas at all?!Thank you so very much for your help!!!