Kabocha squash is a type of winter squash. Kabocha has orange flesh that's sweeter, drier and less fibrous than other winter squash. Even so, most winter squash are interchangeable, and if you can't find one of these Japanese squash, several workable substitutions exist. Unlike summer squash, all winter squash must be cooked. Baking, boiling, steaming, microwaving and sauteing all work well. Store winter squash for up to three months in a dry place at around 55 degrees Fahrenheit.
Acorn squash are one of the more common types of winter squash. They take their name from their acorn-like shape. They're small -- 1 to 2 lbs. and 6 inches around, on average -- so you might need two when substituting these for kabocha squash. It's relatively sweet like the kabocha, so it makes a good alternative from a flavor standpoint. This type of winter squash is particularly well-suited to baking. Look for acorn squash that have mostly green rinds.
Banana squash are so large -- up to 20 inches long and weighing about 12 lbs. -- that they're usually sold in pieces. Their creamy texture is a good match to the relatively fiber-free texture of kabocha squash. The flesh of banana squash has an attractive golden hue that adds to the presentation of any appropriate dish. It adds a slightly more fruity flavor than you get from kabocha. Enhance its sweetness by steaming.
Buttercup squash is an excellent alternative to kabocha squash, sharing many of the same qualities. The coloration of their flesh is basically the same, and the buttercup squash is also a dry and sweet variety. These are usually about 7 inches in diameter and 2 to 4 lbs. Butternut squash works best as a substitute in recipes that call for baking or steaming the squash. Choose a buttercup squash that feels heavy for its size.
Butternut squash looks like an elongated bell. On average, it weighs 2 to 4 lbs. While it's nearly as sweet as kabocha squash, butternut squash is considerably more moist. When substituting this variety in a baked dish, reduce a liquid in your recipe just a little bit. These squash are a popular variety because they have a thin skin that's easy to peel, unlike the tough rinds on most winter squash. Select butternut squash with the most orange rind you see, because it will be the sweetest and therefore the best one to substitute for kabocha squash.
Spaghetti squash is a decent substitute for kabocha squash if the shape and appearance aren't important to the recipe you're preparing. While spaghetti squash has a mild but sweet flavor that makes for a good alternative, the squash separates into crisp, spaghetti-like strands during cooking. This means you won't have solid chunks of squash, as you would with kabocha. Spaghetti squash is oval, about 9 inches long and typically weighing 2 to 4 lbs. Choose spaghetti squash with a very yellow rind.