Finding a good ripe avocado can be difficult. If you get one that's not quite ripe enough to eat but you're dying to make up some tasty guacamole, food blog Tasting Table recommends storing the avocado in a paper bag with a banana.
Photo by Stephanie Dillingham.
Bananas release ethylene gas, which speed up the ripening process for avocados (and other fruits). Storing the two in close proximity means the ripening is super-charged. If you don't have any bananas on hand, apples should work just as well.