Bleach kills cooler mold. Use bleach.

Yes, a diluted bleach solution is the safest and most effective way to kill mold and mildew inside a cooler. Mix one tablespoon of bleach per quart of water, scrub the interior, let it sit for five minutes, then rinse and dry completely.

Vinegar works too if you’re avoiding bleach fumes, but it’s weaker on deep-set mold. Baking soda paste is fine for light surface stuff. The key is not mixing chemicals and making sure the cooler is bone dry before storing it away—mold needs moisture to come back.

Don’t skip the rinse. Nobody wants bleach-flavored ice on their next tailgate.