When you get right down to it, cucumbers sometimes seem the very essence of “why bother?” All you get is a little crunch, a spurt of cool juice and—if you’re lucky—a slightly herbaceous bitterness. Still, when the weather turns hot and humid, when the air is so thick that it sticks to your skin, a bite of something crisp and cool can seem like heaven. That’s when we’re thankful for cucumbers and all the work that has gone into raising them.
It took centuries of breeding just to make cucumbers edible. Wild cucumbers, which are found in the Himalayan foothills, are almost impossibly bitter. That someone once saw promise in this fruit is a tribute to the power of optimism (or extreme hunger). In fact, cucumbers are first cousins of the bitter melon, which is still appreciated in Southeast Asia. Both are members of the Cucurbit family, along with melons and winter and summer squash. As you can tell, this is one of the more varied families in all of horticulture, and that variety holds true with cucumbers as well.
Thousands of years of domestication have resulted in a bewildering variety of cucumbers. Not so long ago it seemed that you could find only one kind of cucumber—the familiar long, dark-green one, usually heavily coated with wax. But today you can find all kinds of cucumbers in the market, seemingly coming from every corner of the globe. There are Persian cucumbers, Chinese cucumbers, Armenian cucumbers, Japanese cucumbers, English cucumbers and Middle Eastern cucumbers. Some are more than a foot long, and others are only as big around as your pinkie. Some are warty; others are smooth. They come in every shade of green and even lemon yellow.
Although this range of variety is fascinating to horticulturists, it is less so to cooks. The one thing all cucumbers have in common is that they taste like cucumbers. Sure, there are very slight variations in degree of bitterness, and some cucumbers are a little crisper than others (although both of these traits are usually more attributable to farming than to genetics).
But other than that, cucumbers are all pretty much the same. Even the so-called lemon cucumbers get their name for the way they look—round and yellow when ripe—rather than the way they taste. The biggest difference between cucumbers, and the easiest way to differentiate among them for culinary purposes, is the thickness of the skin. Cucumbers with very thin skins have always been preferred for pickling (the salt can penetrate very quickly). That leaves cucumbers with thick skins for slicing. Of course, in the kitchen that doesn’t make much sense at all, since thin-skinned cucumbers can be sliced just as easily as thick-skinned. In general, if you have to choose between cucumbers, pick whichever ones seem to be in the best condition rather than favoring a certain variety.
One of the great spurs in modern cucumber breeding has been the fruit’s unfortunate effects on the digestive system. Put plainly, cucumbers sometimes make some people burp . . . a lot. At one time that burpiness was attributed to the seeds, and a lot of effort went into growing seedless cucumbers. These varieties have been developed to set fruit without being pollinated (or even produce almost entirely female flowers). They are cultivated in bee-free greenhouses (locked away in cucumber convents, as it were) to prevent the pollination that causes seeds. (Grown out-of-doors, these varieties will bear seeded fruit.) Unfortunately, although seedless cucumbers do have some culinary merit (the area surrounding the seeds in a cucumber is usually unpleasantly soft and watery), they don’t help with indigestion.
Rather, the very bitterness that is so fundamental to cucumber flavor—and is one of the plant’s more interesting traits—is what causes indigestion. The bitterness in cucumbers comes from compounds called cucurbitacins, which are normally found in high concentrations in the roots, stems and leaves of the cucumber plant rather than the fruit. Cucumbers are one of the more fragile plants a farmer can grow, susceptible to all kinds of fungi, viruses and insects, and these cucurbitacins serve as a kind of natural pesticide, discouraging many bugs from munching away. However, one bug, the cucumber beetle, has evolved with a resistance to the poisonous effects of cucurbitacins. In fact, it is downright fond of the flavor. Not only do cucumber beetles love to eat cucumber plants, but they also harbor harmful bacteria that can cause severe wilt, which can kill the plants. So much for defense mechanisms.
In most cases, cucurbitacins are not found in the fruit in sufficient quantities to spoil the taste. But when cucumber plants are stressed—when the weather turns suddenly hot and dry—they tend to produce fruit that is more bitter. (Perhaps, sensing a threat, the plant is trying to protect its seeds.) Some varieties are less susceptible to stress than others—generally look for anything with “sweet” or “burpless” in the name. Unfortunately, these also taste pretty bland.
Fortunately, you can choose more flavorful varieties and take care of much of the burpiness in the kitchen. Cucurbitacins tend to be concentrated just under the skin and around the stem of the cucumber. So you can reduce (if not eliminate) burpiness by peeling deeply and removing the stem end. This step will be sufficient for most people; however, among those who are extremely susceptible to burpiness, any cucumber will have some effect.
Although they may not look it, cucumbers are very sensitive fruit. More than 95 percent water, they begin to soften almost as soon as they are picked. Without treatment, they should be eaten within three or four days. The most common method used for extending the shelf life of cucumbers is coating them with wax to slow the loss of moisture. This wax is technically edible, but it has an unpleasant greasy quality even when washed. If you can find only waxed cucumbers, peel them.
Another alternative shippers use is sealing cucumbers tightly in plastic. This is more expensive, but it does not leave any residue on the fruit. Water loss is not the only threat to cucumbers. They are also susceptible to chilling damage. If refrigerated for very long, they’ll begin to develop pitting on the surface. Keep them tightly wrapped in the warmest part of the refrigerator (about 50 degrees is ideal) for the best results. Cool as a cucumber, yes, but not too cold.
WHERE THEY’RE GROWN: Georgia grows about a quarter of all the cucumbers in the United States, followed closely by Florida. About 45 percent of the cucumbers eaten in the United States are imported, primarily from Mexico.
HOW TO CHOOSE: Remember that the worst thing that can happen to a cucumber is moisture loss, so avoid any that look shriveled or wilted.
HOW TO STORE: Seal cucumbers tightly in a plastic bag and keep them in the refrigerator. Use them quickly.
HOW TO PREPARE: The only cucumbers that need peeling are those with very thick skins and those that have been waxed. All others can be sliced with the skin on. Some cucumbers have large seed cavities in the center. To remove the seeds, simply carve them out with the tip of a teaspoon.
ONE SIMPLE DISH: A salad of cucumbers and yogurt is so simple and perfect that it is served all around the world. Slice cucumbers into a bowl and add just enough yogurt to dress them lightly. Stir in salt and some fresh herbs—dill is a natural, but basil is good, too. This salad is best prepared just before serving so the cucumbers don’t release too much moisture into the dressing, watering it down.