9 Expert Tips for Picking the Perfect Watermelon

It’s difficult to describe the taste of watermelon, because nothing tastes quite like it. To me, a perfectly ripe watermelon hits you first with a fresh floral but vegetative aroma, then delivers a bright, fruity sugar rush upfront with a rich, lingering sweetness. 

Before diving into this topic, I honestly can’t remember the last time I was able to track down the perfect watermelon. I’ve partly chalked it up to bad luck and partly resigned myself to believing most modern watermelons are simply not what they used to be. But my hope was recently rekindled after speaking with various watermelon experts who gave me nine tips to increase my chances of finding the right one.

But first, where to shop. 

Supermarket vs. Farm-Stand Watermelons

While ripe and delicious watermelons can be found year-round in supermarkets (these are commonly hybrid seedless types developed specifically for commercial production), many of the melons in these stores can be duds, so the odds are stacked against you. 

“Watermelon growers harvest millions of tons weekly, so they’re going through the field and picking everything, not only the ones that are ripe,” says Thanh Truong, a.k.a. Fruit Nerd, a third-generation fruiterer who’s worked at major supermarkets and in wholesale markets.

Farmers must factor in shelf life and transportation. Truong says that melons at peak ripeness would never survive the time and long-distance travel required to get to supermarket shelves. “Ideally, they’re somewhere between 90 to 93% mature, but there can be ones that are 85% ripe in the batch.”

Truong says the difference in flavor is enormous. Anything below 80% ripe is not sweet enough. “A watermelon at 91 to 92% is very sweet,” he says. “But a fully ripe watermelon grown in someone’s backyard, small farm, or market garden will be amazingly juicy, sweet, and crunchy.”

Not only are you much more likely to find a fully ripe melon at your local farmstand in the peak of summer, but you may find watermelons in many sizes (from mini to extra large), shapes (round, oval, blocky, elongated), flesh colors (red, pink, orange, yellow) and rind patterns (from solid to striped or speckled). Truong says watermelons found at local markets would be cultivated for their sugary flesh—not their ability to survive a cross-country road trip.

Still, it is possible to find a sweet and ripe watermelon at a supermarket, you just need to be more prudent when picking.

9 Tips For Picking the Best Watermelons

Whether at a store or farmers market, watermelons with certain characteristics (which we’ll get to in a moment) will be the best of the bunch. These qualities won’t always be obvious, and some methods for selecting ripe ones are more nuanced than others, so do your best.

“Every tip you use might get you a 5 to 10% better selection, but add all the tips together, and eventually you're going to have a watermelon that’s maybe 30% better than the ones literally right next to it,” says Truong.

And no pressure or anything, but picking the right one matters even more since watermelons don’t continue to ripen after harvest. “It'll soften, and the texture may improve a little bit, but it will never get sweeter,” says Amy Goldman, an heirloom seed preservationist and author of The Melon. “What you pick is what you get.”

Matte Skin

Look for a watermelon with dull, waxy-looking skin. “If it looks glossy, it's not ripe,” says Penelope Perkins-Veazie, PhD, a watermelon specialist and professor of horticultural science at North Carolina State University. However, the difference can sometimes be too subtle, even for her, so don’t spend too much time on this one. While shopping, I noticed most watermelons at the store looked matte, so when you see a glossy one, like the one pictured above,  it should stand out like a greased thumb, and make sure to avoid it. 

Full Ends

“Watermelons should also be well-rounded, with filled-out ends,” says Goldman. “If it's not filled out, it means pollination was poor, and the flesh quality suffers.” This is true of both larger, seeded watermelons and smaller seedless varieties.

Bouncy Sound

Tapping watermelons won’t tell you how ripe or sweet they are, but it can clue you in on any damage the watermelon has suffered. “Watermelon is a big bruiser and more fragile than you think,” says Goldman. “I cringe when I see people piling watermelons on each other because that compression damages the texture inside.”

Thumping the watermelons is an option to get at what’s going on behind the rind. (However, it only really works with the large melons, not the minis.) Truong says you’re essentially assessing for reverb. “When a watermelon has a bruised part, the water separates from the flesh, so it absorbs sound,” says Truong. “When you tap it, you want it to sound even and for the vibration to bounce back like a basketball.”

But to be clear, this can be a difficult sound to detect, and some never manage to hear the difference. Even the pros admit it’s pretty hard to assess. “I've thumped these things to the end of the earth, and I can't tell the difference,” says Perkins-Veazie.

Yellow Spot

Look for the ground spot on the watermelon, which is the large, lighter patch on one side. “The spot is where it rested on the ground,” says Goldman. “The spot's color should be a buttery yellow, a sign the farmer picked the watermelon at maximum maturity.” The melon may not have had enough time in the field if it's white. Webbing on the spot is also an excellent sign of sweetness.

Shriveled Stem

Watermelon growers will know that a harvested watermelon is ripe by looking at the calyx, which is the stem area. Truong says if the watermelon is ripe and ready, the stem shrivels, and the melon falls off the vine, but stem tears indicate that the watermelon was forcibly ripped off before it fully ripened. Some melons have a little dried up stem tail still attached, like the one pictured above, making it easy to visually confirm that the stem was brown and shriveled. Some watermelons barely have a stem left, but if they were picked too soon, you can see tears along one side where it was ripped off the vine (below).

Solid Striping

“Look at the striping pattern,” says Perkins-Veazie. “Well-developed stripes mean it's more likely to be ripe.” This is true of the watermelons available to most consumers, but there are heirloom varieties without stripes, so this tip won’t work for those. Goldman adds that if the darker green stripes contain too much yellow, the fruit may be overripe.

Rugged Ridges

“If you look at watermelons closely, they have subtle ridges called veins that run the length of the watermelon,” says Perkins-Veazie. If the ridges look well extended (raised and protruding out—like a pomegranate, but less showy) that's a good indication it’s ripe. They’re definitely visible in larger melons, but not minis. If you can’t see them clearly, feel for them.

Heavy Weight

According to the experts, the watermelon that feels heaviest for its size is likely the juiciest. The easiest way is to pick up several watermelons to compare. I suggest running through all the tips above first to help you weed out the watermelons worth lifting.

Sugar Crystals (For Selecting Cut Watermelon)

If you buy a halved or quartered watermelon, Truong says little sugar crystals near the seeds or false seeds is an obvious sign the watermelon is sweet. In the image above, for example, the flesh around the seeds look like little geodes.

Putting the Tips to the Test

In my quest to pick the perfect watermelon, I purchased six options—three large and three mini  across three vendors (two grocery stores and one farmers market). In each instance, I tried to check all the boxes to get the best possible selection; I also picked one from each shop that was missing some of the qualities to see if they were lacking in sweetness or succulence. 

When I followed all (or most) of the tips together, I consistently picked great watermelons. It’s true what the experts say in that all the tips in combination with each other really pay dividends. When I opted to heed only half of the tips, the watermelon was about half as good.

Most of the tips were easy to assess (especially when I paid no mind to the produce employees teasing me for spending 20 minutes picking out a watermelon). The only one I found a bit tedious was trying to gauge which ones were “heavy for their size.” This tip is easier said than done with the big watermelons. You can’t really pick up two at once, so some muscle memory is required. Mini watermelons are much easier to gauge weight—just hold one in each hand. Goldman’s rounded-ends tip was also helpful in deciding which melons to pick up. The scale at checkout helped me confirm that my prized watermelon was indeed heavier than my second pick by 12 ounces. However, after all that, when I cut the two open at home, the lighter watermelon was sweeter. 

All but one of my melons had beautiful, crisp, damage-free flesh, which means the thumping test likely works. I’m no baller, but I’ve bounced a few basketballs in my life, and Truong’s analogy was spot on. When tapped, a few melons seemed to suck down the sound and vibration, while others sprung it back into my hand. This only worked for the big watermelons though; I didn’t get much feedback tapping mini watermelons, and alas, one of my minis had compromised flesh.

At the end of the day, I was happy to know great watermelons can still be found at the store, but I was even more elated to find a watermelon with lots of crusty webbing over the ground spot at the farmers market; it was the sweetest of the bunch. Just another reminder of the benefits of shopping locally!