The science of a ripe watermelon

Home|Taste|The science of a ripe watermelon

Everyone has their own ideas on how to choose the best watermelon. Maybe you learned this from your parents or even grandparents.

With the rise of the modern grocery store and with worldwide commerce and exchange improving transportation, what was once a seasonal treat has become almost a year-round one. Watermelon — that rich, juicy, sweet red melon — is always a hit, and each year we learn new ways to serve and enjoy this fruit.

This morning I read a short article in the Everyday Physics column in The Wall Street Journal on the physics of sound produced by tapping on a solid object. The sound produced by tapping is an oscillation, its acoustic signature, which is related, as it turns out for watermelon, to the ripeness of the structure of the melon.

Its acoustic signature can tell if the melon has the dreaded air gap inside it. Similarly, if the structure is symmetrical, it will ring like a bell. If you get a note with an identifiable pitch, the fruit is probably solid all the way through. A dull thud indicates that it is asymmetrical on the inside and should best be avoided.

The next question is ripeness. As a watermelon ripens, the flesh becomes more dense but less elastic, and that combination means that a riper watermelon will ring with a lower note. And, although this sounds useful, the complication is that different sizes of melon will produce different notes. The riper the melon is, the lower the note will be. What you hear depends on the size of fruit.

There is no perfect note, but there is a perfect note for a fixed size of melon. This is, of course, where experience comes into play.

A week ago, I spent some time with our daughter. When we went grocery shopping, she gently nudged me out of the way when we came to the watermelon, telling me that she had this. She had read that a sweet melon needed a yellow patch on it to prove its worth.

We all have our own ideas when it comes to watermelon, as well as with life. I guess I’ve been lucky because this year all the melon we’ve brought home has been sweet save for two. Not bad by a long shot.

Susan Woody has been a food writer for more than 25 years and is a member of the Association of Food Journalists.

By |August 9th, 2017|

About the Author: