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Mike Stevens, of Medford, appears to be applying the sniff test in his quest to select the perfect watermelon at Food 4 Less in Medford Wednesday. - Jamie Lusch

Thump Test

The world continues to experience economic distress, war and threats to the environment, but when August heat is upon us the great issues of the day may temporarily take a back seat to that most timeless of quests: How to find maximum relief in the juicy, red depths of that quintessential summer food, the watermelon.

There are many approaches to choosing the perfect melon, including the venerable thump (or slap, tap or knock) test, so we decided to ask some of the area's watermelon experts — or at least people who work daily with produce — to share their secrets.

Ben Prince, who has worked in produce for Ray's Food Place for five years, says he is listening for a solid sound, kind of high-pitched, when he thumps a watermelon, large or mini.

"The more hollow it sounds, the worse the melon," he says. For him, a hollow sound indicates a mushy, overripe melon that will pour out juice when cut open and "doesn't taste good." He also trusts weight, saying that heavier melons tend to be the sweetest ones.

Prince, now third manager at Ray's in Jacksonville, acknowledges people often thump and listen for a hollow sound, but maintains "that's backwards." He says he gets excellent results ("nine out of 10") and repeat requests for help in selecting watermelons.

A series of customers at Food 4 Less in Medford showed that the thump or knock method is very popular among shoppers. Four of seven people who were observed fondling watermelons used percussive techniques to elicit a "hollow sound" before deciding which melon to put into their shopping cart.

One off-duty, male postal worker said he listens for "a firm sound with a ring to it," and most of these shoppers claimed repeated success.

Two women shoppers who selected their watermelons at the same time appeared to know exactly what they were looking for because they chose their melons without any tapping at all.

The first said she just takes the luck of the draw, though she admits to hearing that the heavy ones are best. The other lady laughed when asked to describe her method: "Pray!" she said.

Over at WinCo on Barnett Road, produce clerk Kyle Creasey held a good-sized, seedless watermelon in one hand as he demonstrated his technique of slapping it with the other hand.

Rather than listen to the sound, Creasey, who has six years in the produce business, judges a melon "on how it transfers energy from one hand to the other."

If it's overripe, he said, there's not as much "vibrational conductivity."

Other watermelon buffs informally surveyed this week — along with watermelon websites — cited heaviness, symmetry and a rich, yellow ground spot as clues to sweetness. A pale, white or green spot is widely understood to mean the fruit is not ripe.

A Google search of "watermelon thump test" returned 149,000 hits, including a story on www.pbs.org about a group of science students at West Salem High School in Oregon who wired more than 100 watermelons and thumped them, measured the sound frequencies and correlated the notes to sugar content. According to the article, "students discovered that the more sugar present, the longer a melon's thump would resonate ... so the next time you thump a watermelon, you should be listening for the sound to hang around awhile for a sweet-tasting watermelon."

A rather esoteric technique shared by one local produce worker (who did not care to go on record) involved placing a piece of broom straw or dried grass on the melon at a right angle to its long axis. The melon is deemed sweet if — we're not making this up — the straw moves, compass-like, parallel to the axis.

Daryl Ogren, a produce clerk at Albertsons in Ashland who has been in the grocery business for 30 years, doesn't put much stock in the whole tapping thing. He prefers the surgical approach.

"It's so easy for me to cut it open," says Ogren, who nonetheless waxes almost poetically about watermelons:

"They're kind of like wine — every batch is a little bit unique," he said.

Each pallet or bin of watermelons that arrives at Albertsons is sampled to determine sweetness, with the ripest bins put on sale first. Once a good bin is identified, there is a high probability of success with any of its individual melons, he said.

If, in spite of your favorite testing technique, you wind up with an unripe melon, resist the temptation to compost it. Ogren says unripe watermelons can be sweetened up by cutting them into chunks and refrigerating for two or three days.

At the Ashland Food Co-op, Moreno (just Moreno, kind of like Pele or Madonna), a nine-year veteran of the organic-produce business, also favors the empirical approach.

"You have to try it" to be sure you get a good one, he said. He's tried thumping and slapping but doesn't trust percussion to be reliable.

"There's nothing that's going to take the place of your taste buds," he says.

The Co-op will allow sampling of any organic produce item by a customer, he said, including a big watermelon like the 18-inch-long, 24-pound giant found in one of the outside display bins.

Who needs thumping when free samples are at hand?

David Chuse is a freelance writer living in Ashland.

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