An even quicker method is to put a ripe banana in the bag with the plums. The extra ethylene produced by the banana will cause the plums to ripen fast. [2] X Research source Don’t place the plums in a plastic bag. Using a nonporous bag will prevent fresh air from entering, and the plums will end up having a funny taste. If you prefer, you can ripen the plums by placing them in a fruit bowl, rather in a bag. The plums will still ripen, they just won’t be ready quite as quickly.
Don’t store the bag in a sunny window, as it’s likely to cause the plums to overheat. If the plums get too hot they will begin to rot. Likewise, storing the plums in the refrigerator or at a cold temperature before they are ripe will bring about what is called chill damage. A chill-damaged plum will never become juicy and sweet; instead, you’ll end up with a mealy, tasteless plum.
Observe the texture of the skin. Plums begin taking on a dusty appearance as they ripen. Touch a plum near the tip. When it’s ready, that area will be a bit softer than the rest of the plum. [4] X Research source
