Chewing gum is cheap, I get that. So why make it yourself? I get that, too. But think of all the possibilities that come with creating your own flavors: lemongrass, basil, lemon, and yes, bitters.

Today, most companies’ gum base is a proprietary blend of synthetic and natural ingredients: If a packet lists “gum base” as an ingredient, that gum most likely contains synthetic polymers. The FDA ...