It’s one of the sounds of summer.

Thump. Thump. Thump-thump-thump.

You can hear it in every grocery store’s produce section and farmers market: people tapping watermelons in an attempt to find the sweetest, perfectly ripe one to take home.

Turns out there’s a better way to pick a watermelon. That’s according to a couple of guys who grow them for a living.

Jesse James Wiggins has worked on his parents’ Texas watermelon farm all his life. Along with watermelons, Wiggins Farms also grows onions, cilantro, parsley, dill, corn, cotton, and beets in the towns of Edinburg and Gilley. Wiggins’s rules for choosing the best watermelon—none of which includes thumping—can be summed up in a three-step process: “Look, lift, turn.”

Rob Gibson, farmer and president of the Florida Watermelon Association, isn’t a thumper either. They both shared their best tips.

What's summer without some ripe, juicy fruit to share with loved ones? (by vesi_127/Getty Images)

Look for the Spots and Stripes

First, Wiggins says you should make sure the watermelon looks good on the outside. Check that the surface is smooth with no visible dents, cuts, or bruises.

Then, turn the watermelon; it should have a creamy yellow spot, or belly. This is where the melon was resting on the ground as it grew. A golden color “indicates that it was undisturbed in the spot that it grew and was able to reach maturity,” said Gibson, meaning a riper, sweeter melon. A pale belly may indicate it was harvested prematurely.

But Gibson’s preferred way of picking a watermelon relies on a different visual cue: the stripes. Check the width of the alternating light and dark lines that run down the length of the melon.

“The wider and fuller the lighter lines are, the riper it is,” he said.

Look for a creamy yellow spot on the outside of the watermelon, a sign it was allowed to fully ripen before harvest. (Joe_Potato/Getty Images)

Weigh Your Options

Wiggins says the watermelon should be heavy for its size, which means it’s a full, juicy melon without any empty space.

Gibson suggests comparison shopping with the weight in mind, picking up a few to compare.

“If a melon is light in comparison to another one of comparable size, then it is most likely overripe or hollow,” he said.

But don’t worry about the size itself. While some might think the size of a watermelon affects its sweetness, Gibson says smaller watermelons are the same as big ones as far as taste is concerned.

“Some varieties of watermelon are bred to grow larger fruit,” he explained.

Fine—Give It a Listen

“I have never thumped them; it’s more of a pat. You can pat with a little more force and hear the melon better,” he said. “It should sound solid and not dull. If it sounds dull, it could indicate that it is hollow, bruised, or overripe.”

While farming is a combination of science, brains, and muscle, Wiggins knows Mother Nature still has control.

With these tips, you'll be able to pick out the best of the bunch. (Pantaree Jumpadeang/Shutterstock)

“The consumer should not have to worry about what they are getting—that is our job. But no one is perfect,” he said.

Wiggins says the greatest reward as a farmer is knowing the fruit makes people happy this time of year. Even the seeds bring joy.

“The Wiggins boys are known for winning the seed-spitting contests at watermelon conventions,” Wiggins said. “Some may say it is talent, but a lot of it is practice, and we have a lot of hot air to release!”