Winter Squash

Winter squash varieties are so different that sometimes it’s hard to believe they are related. Their skins may be rough and warty or smooth and sleek, their shapes round or cylindrical. Their colors can range from orange and yellow to green and nearly blue—or just about any combination or variation thereof. Their flesh may be stringy and fibrous or smooth as butter, and their flavor can be sweet and rich or thin and vegetal. Winter squash vary in size from a little bigger than a tennis ball to more than one hundred pounds. Even the name “winter squash” is a misdirection—they are actually at their best in the fall (hence all those Halloween pumpkins). The vegetable acquired its trans-seasonal identity because back in the bad old days before refrigeration (and air shipment), it was one vegetable that could be relied on as a staple late into the frozen months.

Though native to the Americas, squash are grown and loved all over the world—in Europe, of course, but also in Asia and Africa. Partly because of this geographical proliferation, a final count of the many varieties is probably impossible. There are three major species of winter squash: Cucurbita pepo, C. maxima and C. moschata. If you want to tell which is which, check the stems: pepo stems are angular and flared where they attach to the squash; maxima stems are round; moschata stems are smooth and grooved. Each species is broken up into dozens of separate varieties. North Carolina State University’s agriculture department lists more than 350 varieties grown in North America alone. Naming is a quagmire. It seems more the rule than the exception for a single type to have a couple of different names. At the same time, some squash names represent several different varieties. To cite just one example, the name “kabocha” is not only generic but also redundant. It simply means “squash” in Japanese, and the family really consists of several closely related varieties, variations of C. moschata (usually called “Japanese pumpkin”) and C. maxima. Some of the most popular types are combinations of the two.

So what exactly is a winter squash? All the varieties have a couple of things in common. Although they are usually eaten as vegetables, they are actually vining fruits (remember, they contain seeds). They are members of the Cucurbit family, which includes summer and winter squash, melons and cucumbers. Unlike summer squash, winter squash are picked at full maturity, after they have developed a hard shell. (It is this key attribute that discourages spoilage and accounts for the long shelf life.) Many winter squash (though not all) actually improve in both sweetness and general flavor with at least a couple of weeks of storage. They all tend to have golden yellow to buttery orange flesh. On a purely subjective basis, they are almost uniformly beautiful, with rich colors and textures that make them look like elaborately shaped pieces of rustic pottery. But beyond those few similarities, pretty much anything goes.

How do you make sense of it all? The good news is that when you get right down to it, it’s not so hard to pick a winter squash because, quite frankly, you can ignore most of the varieties. Beautiful as they are visually, most were traditionally prized more for their keeping qualities than for any outstanding culinary characteristics. To my taste, there is no better example of that than the hallowed pumpkin, which, in most cases, is a singularly stringy, watery, vegetal-tasting mess. (The squash variety grown for commercial pumpkin pie filling is actually closer to a butternut squash than anything you might recognize as a pumpkin.) So unless you are a cucurbit completist, you should focus on a handful of the best varieties that are commonly available in your area. Several excellent squash may be offered on a very limited basis, such as Hubbard, red kuri and buttercup. And if someone whose taste you trust recommends another variety, by all means give it a shot. In general, however, I suggest the following four varieties, which are both delicious and easily found. (Winter squash seem to be defined by two variables: texture —from stringy to smooth—and flavor —from a nutty sweetness to a kind of green vegetal flavor I’ll call “squashiness” for lack of a better term.)

Whatever the variety, picking a particular squash is a bit of an art. One of the best clues is to inspect the stem, which should always be present and should be dry and corky. This tells you that the squash stayed on the vine until it was almost ready to fall off. (Botanists call this natural separation “abscission.”) The color of the skin should be deep and vibrant, which shows the full development of the chlorophyll and carotenoid pigments that come with maturity. The quality of the color should be matte rather than shiny. Many squash show yellow or golden spots where they rested on the ground, just as melons do. Although this area may be pale, it should be deeply colored as well, and certainly not green. When a squash is fully mature, you won’t be able to nick the skin with your thumbnail.

“Curing” the squash—storing it for a couple of weeks under the proper conditions—improves the flavor of some varieties. During this period enzymes convert much of the squash’s starch to sugar. Indeed, one study found that proper curing (at 75 to 80 degrees and high humidity) for up to three weeks had more effect on the sweetness and flavor of some squash than did an extra week on the vine. This is particularly true of moschata squash, such as butternut and kabocha, and true to a slightly lesser extent of maxima squash, such as red kuri, Hubbard and pumpkins.

Pepo squash, such as acorn, carnival, spaghetti, delicata and sweet dumpling, are closely related to zucchini and other summer squash. They can be cured to harden the shell and reduce the moisture content (improving texture), but they do not convert starch to sugar. They also have thinner skins and do not store as well.

At the market you can spot cured squashes because their colors, though saturated, will be slightly faded. After curing, squash should be stored at cool room temperature (about 50 degrees). Refrigerating them will deaden the flavor and cause pitting and soft spots to occur on the surface.

The flavor and texture of winter squash will vary tremendously depending on how it is cooked. When it is cooked with moisture, such as in steaming, the taste is subtle and the texture delicate. (Normally, you wouldn’t want to simmer squash fully immersed unless you’re making soup, because the flesh is so delicate it will start to dissolve in the liquid.) When it is cooked with dry heat, such as in roasting, the natural sugars caramelize. As the moisture evaporates, the flesh becomes intensely sweet and deeply flavored, and the texture becomes dense and creamy, even buttery. If you’ve never tried sauteing winter squash, you should. The exterior caramelizes nicely, but the interior stays delicate. Even better, instead of taking 45 to 60 minutes to cook (as with roasting), sauteed squash is done in less than 15 minutes.

WHERE THEY’RE GROWN: Most winter squash are at their best from late September through early November. Later than that, you should stick with butternut and kabocha, which will last through December and even into early January. Winter squash in general are not grown widely enough to be tracked separately as a category; pumpkins are grown primarily in Illinois and California.

HOW TO CHOOSE: In general, choose squash that have a hard shell; deep, vibrant colors; a hard, corky stem; and a deeply colored resting spot.

HOW TO STORE: Store winter squash in a cool, dark place. Do not refrigerate.

HOW TO PREPARE: Getting to the sweet inner meat of a winter squash can be a challenge. Some varieties have skins so tough that you have to crack them with a hatchet before you can begin to cook with them. Obviously, unless you have a hatchet in your knife block, stick with the tenderer types, such as butternut or any of the pepos. These can be peeled either before or after cooking. Always peel squash before sauteing, however. With some of the thinner-skinned squash, a reasonably sharp vegetable peeler will be all that’s required. Otherwise, you’ll have to use a chef’s knife. After you peel the squash, cut it in half and remove the seeds and strings. Then dice the flesh neatly. When you’re roasting squash, it’s best to remove the peel after cooking. Before roasting, cut the squash in half and remove the seeds and strings. Place the halves cut side down in a roasting pan with a little water. Roast at 400 degrees, turning the squash cut side up after 20 minutes. Cook until the flesh is easily pierced with a fork, usually about 1 hour. Once the squash is cooked, spoon the flesh away from the skin, if desired.

ONE SIMPLE DISH: Cut the squash in half and remove the seeds and strings. Place the halves cut side up in a roasting pan and add about ¼ inch water. Place a pat of butter in the cavity of each half, salt lightly, cover tightly with aluminum foil and bake at 400 degrees for 30 minutes. Remove the foil and continue roasting, basting the squash occasionally with butter from the cavity, until the squash is quite tender, about 30 minutes more. Dust lightly with freshly grated nutmeg before serving.