Freezing Winter and Summer Squash

Winter Squash

Winter squash varieties for preserving:

• Pumpkin (sugar or pie pumpkins)
• Spaghetti Squash
• Cubed Acorn
• Banana
• Buttercup
• Butternut
• Golden Delicious
• Hubbard squash.

Canning

Pumpkin and winter squash are low-acid vegetables which need to be preserved carefully so no one gets sick from Clostridium botulinum.  Follow specific research tested recipes and procedures to ensure they are preserved safely.

• Pumpkin and winter squash must be canned cubed and never preserved mashed or puréed.
• There is no research-tested recipe for home food preservation proving proper heat penetration to the center of the jar when the squash is mashed or puréed.
• If mashed or puréed squash is canned, the product could still be at risk for botulism.

Freezing

If canning cubed squash is not how you want to preserve it, freezing puree is a great alternative. A tip when freezing food is to not freeze more than 2 pounds of food per cubic foot of freezer capacity per day.

• When preserving winter squash, select mature pumpkins with a firm rind.
• Wash and cut the pumpkin. 
• Remove the stringy pulp and seeds and cut the pumpkin into cooking-sized sections. 
• Cook pumpkin until it is soft by boiling, steaming, in the oven, or pressure cooker.
• Once the pumpkin is soft, scrape the flesh from the peel and mash the pulp.
• Place the container of mashed pumpkin in cold water to cool – stir the pumpkin periodically to cool.
• Package in freezer containers leaving ½-inch headspace in case it expands in cold storage. 
• Seal container and freeze. 
• Store containers in the freezer and use within 1 year. 

Note: To freeze other Winter squash (i.e., Acorn, Banana, Buttercup, Butternut, Golden Delicious, Hubbard, Spaghetti) prepare just like pumpkin above, but note that mashing the cooked pulp of Spaghetti Squash is not necessary.

Summer Squash

If you still have some summer squash producing in the garden, you can also freeze these squashes. Summer squash varieties that freeze well are:

• Chayote
• Crookneck
• Pattypan
• Straightneck
• White scallop
• Zucchini

Freezing

General guidelines for freezing summer squash are:

• Freezing 40 pounds of summer squash will yield 16 to 20 quarts or 2 to 3 pounds for a 1-quart jar. 
• Choose young squash with tender skin.
• Wash the squash and cut it into ½-inch slices.
• Water blanch for 3 minutes.
• Cool in ice water, drain, and package it in rigid freezer containers.
• Leave ½ inch of headspace before sealing and freezing.

Another way to freeze summer squash like zucchini is to freeze it grated for baking applications.

• Choose young zucchini with tender skin.
• Wash and grate the zucchini.
• Steam blanch small quantities of the grated zucchini for 1 to 2 minutes until it is translucent.
• Pack measured amounts needed for baking into freezer containers. Leave ½ inch of headspace at the top of the rigid container.
• Chill the container by placing it in cool water.
• Seal the container and freeze it.
• Thaw rigid containers of frozen zucchini in the refrigerator prior to using it for baking.
• If the zucchini is watery once thawed, discard the water prior to using the zucchini for baking.

For more detailed information on preserving squash by freezing, canning or drying go to our fact sheet Let's Preserve: Squash and Pumpkins.