The Little Tomato Game

There’s nothing like tomato season, those glorious summer weeks when you wonder what to do with all that sweet, tart, bright, red, golden, and green treasure. And then some time in September or October, it’s back to the supermarket if you want a tomato. In his song, “Cry to Me,” the great Solomon Burke declares, “Nothing can be sadder than a glass of wine alone,” but my money is on the watery, flavor-challenged, falsely red fruit you get at supermarkets, especially when you can still taste the symphony of flavors from when you were picking sungolds and a couple never made it into your bag because they were crying out to be eaten on the spot.

But all is not lost. When you go to the supermarket, if you stick to the little tomatoes—the cherry, the plum, the grape (and all the other fruit!)—you’ll find that they nearly always taste better than the big ones.

Store-bought tomatoes have to be transported long distances and they have to arrive uncrushed and unbruised. The riper a tomato is, the softer it is, and the more likely it is to have trouble en route. Many tomato growers pick tomatoes before they’re fully ripe, when they’re edible but before their flavor has fully developed. Little tomatoes, though, are relatively immune to squishage and so they get picked when they’re softer, riper, more flavorful.

Do you want to know why the little guys are so much less squishable than their big siblings? There’s a story to it, and it’s a fascinating one, but it involves some fairly abstract math. Yikes! You may feel like a vegan tricked into eating meat right now: “Gene, I didn’t know there was math in this post! This is The Kitchen Game, not The Numbers Game!” But indulge me. When a bit of math nerdery finds its way into my life, I seize upon it.

The reason ripe little tomatoes have less to fear from a long journey stacked in a box is where things get really interesting. It’s all because of a delightful piece of math, first described by Galileo, known as the Square Cube Law. It’s also why a mouthful of mini M&Ms is an entirely different experience from a mouthful of the regulars and why elephants don’t have fur.

The Square Cube Law describes the relationship between the surface area and volume of an object as it changes size. It states that if you have two objects of the same shape but different sizes, the smaller object will have more surface area per unit of volume than the larger one.

What on earth does that mean? It means that if you have two boxes, one which is twice as big as the other in height, width, and depth, you’ll be able to fit eight times as much stuff inside, but you’ll only need four times as much paint if you want to cover all its sides.

The Square Cube Law applied to M&Ms explains why a mouthful of the regular kind is much more chocolatey than a mouthful of the minis: those little guys have more surface area, and so more candy coating per bit of chocolate.

As for why elephants don’t have fur, animals lose body heat in proportion to the amount of skin they have and, if they’re warm-blooded, generate it in proportion to their size. Little animals, like mice, have a great deal of skin for their size, so they need fur to help insulate some of that heat. Large animals, like elephants, rhinos and hippos, on the other hand, have relatively little skin for their great size. They have the reverse problem from the little guys: they need to take steps to lose body heat, even with their furless skin, which is why they all wallow in mud. (I was introduced to the Square Cube Law in the context of its implications for animal morphology through an article by the brilliant British biologist J. B. S. Haldane, called On Being the Right Size.)

But what about tomatoes? The bigger they are, the heavier they are, and the more force they have on them to squish. Since their skin is what keeps them from squishing, the more skin they have for their size, the less force gets put on any one bit of skin. Ergo, even in winter, little ripe flavor bombs!