How to Tell if a Watermelon Is Bad

Identifying Signs of Spoilage

Check for mold on the outside. Mold or dark-colored spots on the outside of the watermelon could indicate that it has gone bad. The mold might be black, white, or green, and have a fuzzy appearance.

Look for a healthy color outside. The watermelon should have either a consistent pine green shade or a striped appearance. Striped watermelons have alternating lime-green and darker pine-colored stripes.

Look for a deep pink or red inside. These colors indicate the watermelon is healthy. If your watermelon is a different color (black, for instance), do not eat it. Different varieties of watermelon have different internal appearances. Desert King, Tendergold, Yellow Baby, and Yellow Doll watermelons have yellow or orange flesh.

Beware of gritty and dry watermelon flesh. When watermelon is no longer good, the crisp flesh will start to shrivel. The flesh might even be pulling away from the seeds. In other cases, the watermelon might become slimy and mushy.

Smell the watermelon before cutting into it. A healthy, edible watermelon should smell sweet and fresh. If it smells tangy or sour, it’s gone bad and should be thrown it away.

Measuring the Freshness Using Dates

Use the expiration date. If you’re eating pre-cut watermelon you bought from the market, the container should include an eat-by, use-by, or another expiration date. This date lets you know how long you have until the watermelon goes bad.

Eat cut watermelon within five days. Properly stored, sliced watermelon will stay good three to five days. Make eating it a priority to prevent it from going bad.

Eat unrefrigerated, uncut watermelon within 10 days. After about a week, uncut, unrefrigerated watermelon will start to turn. Eat uncut, unrefrigerated watermelon as soon as possible.

Don’t eat refrigerated, uncut watermelon after 2-3 weeks. After about two weeks, refrigerated, uncut watermelon will start to turn. To prevent your uncut, refrigerated watermelon from going bad, eat it within two weeks of purchase.

Extending the Shelf Life of Watermelon

Refrigerate your whole or sliced watermelon. Watermelons are typically refrigerated at a temperature of 13 degrees Celsius (55 F). Storing your fruit at 21 Celsius (70 F) will increase its lycopene and beta-carotene content (both of which are important antioxidants).

Store cut watermelon in an airtight container. A resealable bag or container is the best place for watermelon. This will preserve its flavor and freshness. In a pinch, wrap your watermelon tightly in aluminum foil or plastic wrap.

Use caution when freezing watermelon. Some people advise against freezing watermelon altogether, since thawing or cutting open a frozen watermelon piece could cause the juice to drip out. If you decide to live on the wild side and want to freeze your watermelon, place it in airtight containers or heavy-duty freezer bags. The watermelon will stay good for 10-12 months.