A smooth mix of dissimilar substances is an emulsion. Keeping them mixed is called emulsification. Something that does this is an emulsifier. I don't know what

A smooth mix of dissimilar substances is an emulsion. Keeping them mixed is called emulsification. Something that does this is an emulsifier. I don't know what it is, and it could be something natural, but what was there and now isn't is some kind of emulsifier.