You know the feeling: You glance in your water bottle and your stomach sinks when you realize you haven’t washed it in…quite some time. Experts recommend washing water bottles after every use, plus doing deep cleans every once in a while to prevent contaminants from forming in them.
With over 100,000 species of mold in the world, colonies can come in a variety of colors, shapes, and textures. Rubino suggests looking for any green, white, gray, blue, red, black, or brown formations in your bottle. It may appear fuzzy, powdery, velvety, or slimy. “If any type of unidentifiable growth pops up, it’s safe to assume there’s mold,” he says. “If mold is in the bottle, get rid of it.”