How to Tell if a Watermelon Is Bad

Co-authored by wikiHow Staff

Last Updated: November 11, 2022 References Approved

Watermelon is a delicious summer treat, but to protect your health, it’s important to know if a watermelon is bad. One way you could discover whether your watermelon is bad is by checking for mold or a foul smell. You could also use the expiration date to tell if the watermelon is bad.

Method 1

Method 1 of 3:

Identifying Signs of Spoilage

1
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.^{[1]
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2
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.^{[2]
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3
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.^{[3]
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- Different varieties of watermelon have different internal appearances. Desert King, Tendergold, Yellow Baby, and Yellow Doll watermelons have yellow or orange flesh.^{[4]
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4
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.^{[5]
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Research source} In other cases, the watermelon might become slimy and mushy.
5
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.^{[6]
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Method 2

Method 2 of 3:

Measuring the Freshness Using Dates

1
Use the expiration date. If you’re eating pre-cut watermelon you bought from the market, the container should include an eat-by, best-by, or another expiration date. This date lets you know how long you have until the watermelon goes bad.^{[7]
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2
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.^{[8]
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3
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.^{[9]
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4
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.^{[10]
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Method 3

Method 3 of 3:

Extending the Shelf Life of Watermelon

1
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).^{[11]
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2
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.^{[12]
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- In a pinch, wrap your watermelon tightly in aluminum foil or plastic wrap.^{[13]
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3
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.^{[14]
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Research source} 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.^{[15]
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