Watermelon is a sweet summer treat that has been a Southern favorite for generations. When you bite into a watermelon, what you want is juicy, sweet goodness. But if the watermelon isn't fully ripe, you end up with watery sadness. Nobody wants that. You can avoid serving an unripe watermelon by learning to tell whether or not a watermelon is ripe before you slice into it and find out with a mouthful of flavorless disappointment.
Unlike other types of summer fruit, you can't give a watermelon the sniff test to determine whether it's ripe and ready to eat. When it comes to watermelon, you have to use your eyes and ears instead. Whether you're buying watermelon from the grocery store, the farmers' market, or off the bed of a pick-up truck, look (and listen) for these signs of a ripe watermelon.
Check The Stem
If the melon still has a bit of its stem attached at one end, you want to select one that is brown and dry rather than crisp and green. While a hard, green stem is an indication that the watermelon was harvested recently, its greenness also means that the melon didn't get enough time to ripen on the vine. The best-tasting melons have no stem, because they were allowed to ripen until they fell off the vine. Unfortunately, an under-ripe melon won't continue to ripen after it's picked. Try using it in savory recipes like this Tomato and Watermelon Salad.
Look For A Yellow Belly
When a watermelon is ripe, you'll see a patch of creamy, yellow rind on the underside. This area is called the ground spot—or belly spot or field spot—because it's the part of the melon that touched the ground and wasn't exposed to sunlight as it grew. If you can't find the field spot, it's likely that the melon was harvested too soon and didn't have a chance to fully ripen. If you find a field spot that's small and white or greenish-white instead of yellow, that is an indication that it may have been picked from the vine too early. A large yellow ground spot is the best sign that the watermelon is ripe and plenty sweet.
Find The Sugar Spots
Brown webbing or tiny black dots called sugar spots are a sign that the melon is practically brimming with sugar and will be quite delicious. These spots are an indication that sugar leaked through the rind, so it's ripe and ready to serve plain or in your favorite watermelon recipe.
Sugar spots are not to be confused with the soft brown or white patches that come along with belly rot, a condition that speeds up the molding process. A melon with belly rot will not only have a bitter taste, but it might also make you sick. Avoid these at all costs.
Choose A Uniform Melon With Dull Skin
Give the rind a close inspection on all sides. Avoid watermelons with cuts and soft spots, but surface scratches are perfectly fine. It's also okay if the rind on the top of the melon looks a bit faded—that is due to sun exposure, and another sign of ripeness. The skin should look dull, not shiny. Shinier rinds are newer rinds, and that means the melon has not had enough time to mature. You want a melon with a duller look, which indicates that it has spent enough time ripening on the vine.
With watermelon that is lumpy or irregular, the fruit likely received inconsistent amounts of sun and water while growing, and that means the taste is probably inconsistent, too.
Should You Thump Watermelon?
Opinions vary as to whether or not you should thump a watermelon to test its ripeness. It may sound silly, but some say you should lightly rap your fist on the underside of the melon and listen for a deep, hollow sound. This is supposed to indicate that the melon is plenty juicy and ready to eat. According to this theory, you should pass on the melon if the thumping results in a dull sound or if the rind feels soft. An unripe melon will have more of a ping and should also be passed over. However, not all can master this art. Fortunately, there's a more foolproof way as we describe below.
Feel The Weight
The easiest way to tell whether a watermelon is ripe is to simply pick it up. A ripe watermelon is full of water. It should feel weighty in your hands, no matter its size. But you can't really be expected to know how much a watermelon of any given size should weigh. So, the best way to determine which melon is weighty enough is to pick up two or more melons of approximately the same size. Then, your best bet is to choose the heavier melon.