What is winter squash?

Butternut squash: elongated, with thin beige skin and orange, sweet, and fairly moist flesh. It is hollow only in the round part; the neck is solid flesh, which is why it is so efficient when cut into cubes. It works well roasted, in purées, and in creamy soups like butternut squash soup.

Kabocha (Japanese pumpkin): round and flattened, with dark green skin and light speckles. Its flesh is the driest, starchiest, and sweetest of all: it makes the thickest purée and is the best at holding a filling. The skin is edible when cooked. This is the variety used for stuffed squash.

Hubbard squash: large, with a grey-blue, extremely hard skin and firm, yellow flesh. It is a storage squash—it lasts for months whole—and is the traditional choice for locro.

Criollo: large, usually sold in pieces. Its flesh is less sweet than the kabocha and is used in dishes where the squash needs to break down and provide body, such as humita in a pot.

Halloween pumpkin: round, orange, with thin skin and thin walls. It is selected for carving, not for eating: its flesh is watery and lacks flavor. In the Northern Hemisphere, it is everywhere in October; in the Southern Hemisphere, it is rarely found. For carving, see the lantern tip.

The difference that matters in the kitchen is how much water and starch the flesh contains. Dry, starchy squashes, such as kabocha and butternut, make thick purées, fillings that set, and roasts that brown well. Watery ones are better for soups and stews, where the water content is not an issue.

This is why pumpkin pie with mascarpone combines butternut and kabocha: the moist sweetness of one and the body of the other. And this is why in the United States, canned purée for pumpkin pie is not made with Halloween pumpkins but with dense-fleshed varieties, relatives of the butternut.

Cooking method also affects water content: roasted, the squash loses water and concentrates flavor; boiled, it absorbs it. For purées, pies, and breads, it is best to roast it in halves, cut-side up.

Almost all edible squashes come from three species. Cucurbita maxima includes the kabocha and the Hokkaido squash sold in Europe; Cucurbita moschata includes the butternut and most dense-fleshed varieties for purée; Cucurbita pepo includes the Halloween pumpkin and also the zucchini, which is the same species but harvested young.

The cayote, used for sweets in the northwest, belongs to a fourth species, Cucurbita ficifolia. Names change by country: what is 'anco' here is 'calabaza violín' in Spain and 'butternut' in English; the 'cabutia' is the 'kabocha' of Japan.