Melon salad with shrimp and wild arugula

Some people say you should thump them. Some say you should give them a sniff. Some claim the secret is all in the skin. Some tell you to play with their bellybuttons.

They’re all right and they’re all wrong when it comes to choosing melons. It seems almost cruel that something so purely pleasurable can be so complicated to choose.

A good melon ranks among late summer’s most luxurious treats -- melting yet still slightly crisp in texture, sweetly redolent of flowers or musk or honey, or all of them combined, depending on the variety. Can there be anything sweeter on a hot evening than feasting on cool wedges of melon, draped with silken sheets of prosciutto?

On the other hand, a bad one tastes like an undistinguished cucumber.

Telling the difference between the two is the key. And how you do that depends on a number of factors, depending on what kind of melon you’re talking about (and, come to think about it, just exactly what it is you mean by “melon”).

The good news is that once you’ve got a great melon, you’re 90% of the way to a great dish.

When Alain Giraud was cooking at Bastide, one of his signature appetizers was an almost paper-thin sheet of spiced cantaloupe wrapped around a crab salad. It was magnificent.

But even if you’re not a star chef who can execute something so technically demanding, you can still make great melon dishes. Some of the best are simple almost to the point of seeming Zen. Try serving a slice of melon with nothing more than a simple grinding of black pepper. The sharp, floral elements of the pepper are a perfect contrast to the lusciousness of the fruit.

For the same reason, herbs like arugula, basil and mint seem to be natural accompaniments as well. You might never have thought of using such a sweet fruit in a savory salad, but given a restrained hand and the right mix of ingredients, it can be exactly right for a summer supper.

Really salty ingredients are also perfect foils for melon’s sweetness. Cut a melon in chunks and drape it with prosciutto. Or spear a piece of melon on a toothpick along with a bite of salty dried sausage.

For dessert, lightly sauce sliced melon with a simple syrup flavored with mint and lime zest, or maybe slivered fresh ginger (this is particularly nice if you use a mix of melon varieties with varying colors and textures). Or cut a melon in half and fill it with either a Muscat-based wine or Port. White Port is even better. (This can also be served as an appetizer.)

Some people puree melon and serve it as a cool, sweet summer soup for a first course. Personally, I’d rather have it as a dessert, maybe garnished with a little sweetened yogurt and some berries. It’s but a short step from dessert soup to sorbet. Just don’t sweeten the liquid too much -- melons are high enough in sugar on their own.

But before you get creative, you have to have a good melon. And that’s where things get complicated.

While once our choice of melons was limited (they came in green honeydew or orange cantaloupe), today you can find an amazing assortment: Ambrosia, Galia, Persian, Sharlyn, Ha’ Ogen, Crenshaw, Casaba, and yes, there is a Santa Claus.

Those are just a few. Particularly now, as the melon season enters its victory lap, talk to a farmers market grower such as Alex Weiser and you can add Sugar Queen, Charentais, Sugar Nut, Butterscotch, Valencia, and even something called Piel de Sapo (“skin of the toad”).

Call me a contrarian, but the other day I came home with an orange-fleshed honeydew and a green-fleshed cantaloupe. I was just choosing the melons that seemed best. I wasn’t wrong. The honeydew seemed to have all of that variety’s floweriness, but with a more luscious texture. The cantaloupe seemed even sweeter than normal, with its musk lightened by a little honey.

Because family matters so much with melons, picking the right one must begin with a little lesson in botany. It will come as no surprise to anyone who has paid them more than a glance that melons are members of the gourd clan, along with squashes. Collectively, these are known as cucurbits. The specific family that includes melons (well, most melons) is Cucumis. As you can probably tell by the name, it also includes cucumbers.

Within the Cucumis family, melons are subdivided into several groups -- how many depends on whom you’re talking to. The first group is called Inodorous. They are smooth-skinned melons like the Casaba and the honeydew. They usually have green flesh, but not always). Inodorous melons tend to be very sweet, have a fairly crisp, slightly grainy flesh and a honeyed quality to the flavor.

The second important group is Cantalupensis. These are melons with rough skins and usually with orange flesh. As you could probably guess, these include cantaloupes. But wait. What you probably think of as a cantaloupe isn’t a cantaloupe at all. It’s a muskmelon. Some botanists recognize a third class of melons, which have netted skins. They call these Reticulatus, and the melon we usually call a cantaloupe is one of them.

A true cantaloupe is a melon like the French Charentais or Cavaillon (cantaloupe is the “Franglization” of the Italian Cantalupo, which was the name of the pope’s summer estate outside of Rome. Supposedly it was one of those 15th century gourmet popes who had these brought from the Near East).

These true cantaloupes have skin that is roughened by scales, rather than netting. They are also ribbed. Their flavor is intensely flowery and almost invariably inspires the same in writers trying to describe it -- “ambrosial” would be considered mild praise. Probably the most commonly available true Cantalupensis melon in the United States is the Israeli import Ha’ Ogen.

Fortunately for cooks, other than the texture of the skin, Cantalupensis and Reticulatus melons are pretty much the same: Their texture is smoother and more melting than the Inodorous melons; they might be slightly less sweet, but their flavor and aroma are more powerfully floral, to the point of muskiness.

All in the family

At the rate that farmers are experimenting with new varieties, attempting to memorize the ins and outs of the various melon families would be a Sisyphean task. Instead, just keep in mind the difference between the smooth-skinned and rough-skinned melons, because each of these families reveals its quality in different ways.

Rough-skinned melons are the easiest to choose, because they give you so many clues. The first thing to check is the netting or scaling. In a mature melon, this will be tan or golden in color and definitely raised above the background skin, which should be golden in color, not green. Some rough-skinned melons are also ribbed. In a mature melon, those ribs will be pronounced.

Inspect the skin also for the pale, smooth spot the French call the couche, which is the place where the melon rests on the ground. It should be creamy or golden. It, too, should be pronounced, but ideally not too much so. If there is no couche, it probably means the melon was picked too early. If the couche is too big, it’s a sign that the melon rested in one place for too long.

A clean bellybutton is important, but you knew that, right? All rough-skinned melons are harvested at what farmers call “full slip,” which means the fruit pulls cleanly away from the vine, leaving no trace of a stem in the bellybutton.

One of the best ways to choose a rough-skinned melon is also the most obvious: Give it a whiff. When fully ripe, these melons develop a heavenly musky floral perfume that you can smell at the other end of the produce section. Remember, though, that it is but one step from fully ripe to overripe. Melons can be too soft and too fragrant.

Sadly, the only one of these clues that works for smooth-skinned melons is the couche. There’s no way around it: These fruits are devilishly hard to choose. They don’t have netting, so you can’t check that. They don’t “slip” from the stem, so the bellybutton is no help. They usually don’t even have a smell (hence the name Inodorous).

The first thing to look for is color. This is extremely subtle, the difference between a “hard” green or white and a “creamy” color. But if you look at several, you’ll see the distinction. Though the skins of these melons are smooth, when they are fully mature they will develop a slightly waxy texture.

The best indicator of quality I’ve found in smooth-skinned melons is what growers call “sugar spots.” These are brown flecks on the surface. Unfortunately, you’ll only see them at farmers markets. Supermarket produce managers tend to regard them as imperfections and wash them off.

Remember that there is a difference between ripeness and maturity. Melons will continue to ripen after picking -- the flesh will soften and the aromas and flavors will become more intense -- but they won’t get any sweeter. This softening is usually most evident at the blossom end of the fruit. Press gently; if there is a little give, the melon is ripe.

If you have a melon that is mature but still feels very firm, leave it at room temperature for a couple of days. Melons can be refrigerated, but only after they’re ripe.

So much for the Cucumis melons. The elephant in the room that we haven’t discussed is the watermelon, perhaps the most popular melon of all -- at least in the United States. Watermelons belong to a different branch of the cucurbit family entirely: Citrullus. Its closest relative is the bitter apple, a small, hard fruit that can be poisonous in moderate doses.

And there isn’t enough time left in the summer to go down that tangled path.