Off the vine, winter squash look like some kind of exotic rustic pottery, with rich colors and textures that give them the appearance of having been elaborately carved and colored. That beauty makes them one of nature’s more versatile vegetables: Until you’re ready to eat, you’ve got a holiday centerpiece.
But once you cook them, they transform completely, that ceramic hardness giving way to a nearly creamy texture and a subtle, nutty sweetness. Of course, that’s not going to happen with just any winter squash.
Beautiful as they are, squash can be confusing. Even the name can fool you -- winter squash are actually harvested in the fall (hence all those Halloween pumpkins). We call them winter squash only because most varieties have hard, thick rinds that allow them to be stored through the cold winter months when, traditionally, few other vegetables were available.
Winter squash can be rough and warty, or smooth and sleek. They can be round or cylindrical. The skin can be orange, yellow, green and even nearly blue -- or just about any combination or variation thereof. Their flesh can be stringy and fibrous, or smooth as butter. The flavor can be sweet and rich, or thin and vegetal. Winter squash range in size from a little bigger than a tennis ball to more than 100 pounds.
How do you make sense of all this? The good news for cooks -- this may sound cynical, but it’s true -- is that you can ignore most of them. To put it diplomatically, most winter squash were traditionally prized more for their keeping ability than for any outstanding culinary characteristics.
I know that’s harsh, but you are best off focusing on a handful of the best commonly available varieties. In general, winter squash seem to be defined by two variables: texture -- from stringy to smooth -- and flavor -- from nutty sweetness to a kind of green vegetable flavor we’ll call “squashiness” for lack of a better term.
* Acorn. This is probably the most familiar winter squash after the pumpkin and almost certainly the most familiar one that is edible. Its skin is dark green with occasional blushes of saturated orange. Its flesh is pale to medium orange. The texture is semi-smooth and rich, and flavor is moderately sweet and moderately squashy. The acorn is a middle-of-the-road squash. The Table Queen is an especially good type of acorn.
* Butternut. If I had to choose a single readily available winter squash variety, this would be it. The butternut is shaped like a long cylinder with a slight bulb on one end. The skin is fairly thin and a kind of golden tan in color. The flesh is dark orange and semi-fibrous. The flavor is very sweet and nutty with just a hint of green squashiness.
* Carnival. This looks like a harlequin acorn squash, with beautiful patchwork dark green and bright orange skin. The flesh is dark orange and slightly fibrous. The flavor is complex, rich and sweet with an intriguing earthy note.
* Kabocha. Though it became available only in the last decade or so, the kabocha seems to be everywhere today. It is round and slightly flattened at the top and bottom. The skin is dark green with delicate gray-blue tracing (there are also all-green and dark-orange versions). The flesh is pale to medium orange and extremely dense and smooth. The flavor is very sweet but with a nice green squashy edge that gives some backbone.
Whatever the variety, there is an art to picking a good winter squash. One of the best clues is the stem (which should always be present). It should be dry and corky. This tells you the squash stayed on the vine until it was almost ready to fall off, which happens at full maturity.
The color of the rind should be deep and vibrant, which shows the full development of the pigments that come with maturity. And for the same reason, it should be matte rather than shiny. Many squash show pale spots where they rested on the ground, just as melons do. Most squash have thick, hard skin. When fully mature, you won’t be able to nick it with your thumbnail.
One important and often overlooked fact is that many winter squash varieties actually improve after picking, provided they are properly stored. This is particularly true of squash such as butternut and kabocha, and true to a slightly lesser extent with squash such as kuri, pumpkins and hubbards.
Squash such as acorn, carnival, spaghetti, delicata and sweet dumpling do not improve after picking.
The squash that do improve will certainly be sweet immediately after picking, but their sweetness and depth of flavor will increase for several weeks. During this period, enzymes convert much of the squash’s starch to sugar. Indeed, one study found that proper curing (temperatures of 75 to 80 degrees and high humidity) for up to three weeks had more effect on the sweetness and flavor of some squash than an extra week on the vine.
The flavor and texture of winter squash vary tremendously depending on how it is heated. Cooked with moisture, such as by steaming, the taste is subtle and the texture is delicate.
Simmered into a risotto, for example, the squash flavor is subtle, little more than a haunting sweetness. Toasted walnuts provide a complementary flavor and a contrasting crunch, and flash-fried sage leaves add an autumnal perfume.
When cooked with dry heat, such as by roasting, squash comes on strong. Not only is there delicious caramelizing of the natural sugars, but with its moisture driven off, the flesh of the squash will be dense and creamy, even buttery.
Roasted squash can be served just as is (at least in the case of smaller acorns), or you can spoon out the pulp and puree it in the food processor with some butter and seasonings. Because squash have a different type of starch than potatoes, they won’t turn gluey. Thin the puree with stock and you have a wonderful base for a winter soup.
If you’ve never tried sauteing winter squash, you should. The result is somewhere between moist- and dry-heat cooking: The exterior caramelizes nicely, but the interior stays delicate. Even better, instead of taking 45 minutes to an hour the way roasting does, sauteed squash is done in less than 15 minutes.
Cooked this way, winter squash can stand up to the most robust of flavorings. To keep it quick, finish the dish simply with a spoonful of rosemary gremolata, a minced combination of fresh rosemary, garlic and lemon zest (the original is made with parsley and used to garnish osso buco).
The mixture cooks in a flash, and though the individual components are powerful, the result is a perfume that flavors the squash without overpowering it.
Thankfully, with winter squash, beauty is more than skin deep.