How to Roast Butternut Squash

Come fall and winter, well after juicy tomatoes and sweet corn have faded from market stands, butternut squash steps in to become the star ingredient in many kitchens. Butternut squash is a member of the cucurbita family, along with other winter squash varieties like delicata, acorn, kabocha, and red kuri squash (not to mention the larger gourd family of cucumbers, melons, and summer squash). The vegetable’s deep orange flesh is sweet and starchy, and its versatility makes the ingredient a favorite among many home cooks who use it in salads, soups, pastas, and more. 

I often use butternut squash in place of pumpkin when cooking. Barring the major aesthetic differences in shape and size, butternut squash is very similar in taste and texture to pumpkins, and is often even sweeter and more flavorful than pumpkin itself. Once the squash is harvested, it’s left in storage to “cure” for 10 to 14 days before it is sold and eaten. As the squash sits, the plant converts starches into sugars, which become more concentrated and results in a richer, more flavorful vegetable.

What to Look for When Buying Butternut Squash

Whole, fresh butternut squash is hardy and can last for up to three months when stored in a cool, dry place. Though it can be difficult to gauge the ripeness of butternut squash, you’ll want to look for a gourd that feels hefty and is firm to the touch, but sounds hollow when tapped. It should go without saying, but avoid moldy, bruised squash. Many grocery stores sell prepped butternut squash that’s been peeled and cubed—while this is convenient and will work in a pinch, the flesh has been exposed to air for much longer and is therefore likely to spoil much faster.

What About Frozen Butternut Squash?

Like prepped fresh squash, the frozen stuff is incredibly convenient: there’s no need to peel, deseed, or chop. Depending on what you’re cooking, frozen butternut squash may be a suitable alternative to using fresh. Freezing vegetables causes the water to expand and ice crystals to form and puncture cell walls, and as the vegetables thaw, the water melts and causes the vegetables to weep and become soggy. For crisp, roasted squash—or any preparation where you want the squash to hold its shape—you’re better off using fresh. But if you’re planning on making a blended soup, mash, purée, or other recipe where the structural integrity of the vegetable isn’t important, frozen will work just fine.

How to Store Butternut Squash

According to the Oregon State University’s Department of Horticulture, squash should be stored between 50º to 55ºF; any cooler, and the squash will quickly decay and dry out on the inside. The gourds should be kept in a dry place and away from ripening fruit that releases ethylene gas, like apples, pears, and bananas, as this may shorten their shelf life.

To store squash in your freezer, peel the vegetable, remove its seeds, and cut into 1-inch cubes. Lay the cubes flat on a parchment-lined sheet tray and place in the freezer. When frozen, you can transfer the squash into a freezer-friendly zip-tip bag.

How to Prep Butternut Squash

To cut butternut squash, start by trimming the top and the base. To peel the squash, hold it in one hand, and run a sharp peeler down the sides of the gourd to remove its skin. If the squash is too firm to peel with a peeler, you can remove the skin with a sharp serrated knife or soften it in the microwave. For the microwave method, place the squash in a microwave-safe bowl with some water (two tablespoons of water for every pound of squash) and microwave on high in three minute intervals.

Once peeled, cut the squash in half lengthwise and use a large spoon to remove the seeds and any stringy pulp. Discard the seeds or set them aside for roasting.

Popular Butternut Squash Cooking Methods

While this guide is focused on roasting—the method we use most often for butternut squash—there are multiple ways to cook the vegetable. Here are some of the most common:

• Boiling: Though you won’t get the crisp, caramelized exterior that comes with roasted squash, boiling is a quick, effective way to cook the vegetable. Boiling does leach flavor from the squash into the water or broth it’s cooked in, which isn’t ideal if you want to drain and serve the squash. But if you’re planning to purée the squash with the cooking liquid for soup or serve the squash in a broth, that’s fine, assuming the less sweet, less complex flavor of unroasted squash is what you're after. To boil squash, fill a medium pot with 4 cups of water or broth, then simmer one 2 1/2-pound butternut squash (peeled, seeded, and cut into 1-inch cubes) with salt, to taste, until tender, about 8-10 minutes.
• Steaming: Another equally speedy way of cooking squash is to steam it, and you won’t lose as much flavor to the cooking liquid as you would if boiling. Like boiling, though, it also does little to develop the sweetness or complexity of the squash flavor; that can be desirable in some recipes, where the squash's clean, natural flavor is what you want. To steam, add two inches of water to a large saucepan fitted with a steamer basket and bring to a boil over high heat. Place the squash in the steamer basket, cover, and steam until tender, about 15 minutes.
• Microwave: To cook butternut squash in the microwave, it must first be cut in half and then cored. You’ll place the cut-side down on a microwave-safe plate, then cook it in four to five minute intervals on high until tender. This method is similar to boiling and steaming in that you get none of the caramelization or Maillard reaction that enhances sweetness and depth as you do when roasting, but it's quick and convenient, and doesn't involve the stovetop.
• Roasting: Roasting deepens squash’s flavor and brings out its sweet, savory notes. As Serious Eats contributor Mari Uyehara wrote in her guide to winter squash, roasting “concentrates the squash’s flavor by evaporating moisture, converting its complex carbohydrates to sugars, then caramelizing those sugars.” And the Maillard reaction—a series of chemical reactions that occur when proteins and sugars in food are transformed by heat—helps produce complex, bittersweet flavors. 

As mentioned above, in most instances, we find roasting to be the ideal way to prepare squash. It's worth noting that you can also combine methods, for example first roasting and then simmering the squash: We often recommend roasting your squash before adding it to soups and stews for a more flavorful final result.

To speed up the squash’s caramelization in the oven, you can toss the vegetable with a pinch of baking soda before placing it in the oven. Baking soda also helps to soften and break down pectin, a fiber that contributes to the firm texture of squash, which is helpful when mashing or puréeing the squash after. 

The Best Temperature for Roasting Squash

While a lower temperature like 375ºF (190ºC) may be ideal for certain vegetables like carrots and parsnips, we’ve found 400ºF (204ºC) to 425ºF (218ºC) to be the best temperature range for roasting squash in the oven. Roasting at these temperatures brings out the gourd’s sweetness and results in slightly crisp, caramelized edges and a tender, creamy interior.

The Best Fats for Roasting Squash

Any neutral oil—vegetable, canola, or grapeseed—is suitable for roasting. But if you’re looking for a versatile oil that’s also flavorful, we recommend using olive oil. Because of olive oil’s low smoke point of 325 to 375ºF (165 to 190ºC), some people may hesitate to cook with olive oil when using high heat, but there isn’t any credible evidence that it’s bad for your health, so go ahead and roast your butternut squash in olive oil without worry.

Alternatively, butter, ghee, and coconut oil are also good options for roasting squash. Ghee, which is clarified and lacks the water, proteins, and sugars of butter, is less likely to burn at high temperatures and will lend your squash a rich, nutty flavor. If you’re roasting squash in butter, you may see enhanced browning because of the sugars and proteins in the dairy—just be careful that there may be a higher chance of burning if you aren’t watching your squash closely.

Keep in mind that unrefined coconut oil will impart a tropical flavor onto your squash, which may be suitable for some recipes but may not be what you’re looking for in others. For coconut oil with a more neutral flavor, look for refined coconut oil instead.