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How to Can Winter Squashes and Pumpkins: An Illustrated Guide

Butterfly has been gardening and preserving food of all kinds for many years, and she thrives on the creativity involved in these processes.

After the squashes have served their decorative purposes, then what?

After the squashes have served their decorative purposes, then what?

Pressure Canning Is a Good Way to Preserve Leftover Squash

Winter squashes are one of my favorite parts of fall. I am anxious over their growth periods each spring and summer, doing my best to deter the hordes of hungry grasshoppers and the occasional pecking chicken in my garden. I invest many prayers asking that they mature before the first hard freeze. Then, when at last their golden and orange, buff, spotted, and streaked rinds adorn my table and cellar, I breathe many prayers of thanksgiving and begin to work out my plans for them.

There are pumpkin pies to make and butternut squash custards with nuts on top to bake—halved acorn squashes with their insides running with butter and dotted with black pepper to set before my appreciative husband. There are cookies and muffins and pancakes and, yes, even pumpkin ice cream to look forward to.

I often have a cellarful of squashes when the first heavy snows fly. But around February, the squashes begin to lose their keeping qualities. Nobody wants to be served a spaghetti squash that looks like it has the measles. So what is the answer?

You're not supposed to dry winter squash, nor pumpkins. Why? I don't know yet, but I suppose it has something to do with bacteria which may spoil the squash and hurt you. Freezing is an alright answer, but bags of puree take up so much space. So my answer is canning.

Which Kinds of Squashes Are Eligible For Canning?

Almost any squash can be canned. However, all squashes are low-acid foods, so must be processed using a pressure canner or pressure cooker. Even summer squash varieties can be canned, and very large or overly mature summer squashes should be processed just like winter squashes.

A Note on Preparing Squashes for Baking

Large squashes must be cut apart before stewing or roasting, due to their size. Smaller ones may be roasted whole. Place only a small amount of water in the bottom of the roaster or pot, as the squashes will give off their own liquid.

If you have many squashes to bake, change the water every batch or two, especially with pumpkins, which seem to do a good job of cleaning water lime and other residues from the bottoms of pans. I had a batch of pumpkin nearly ruined when they helped bake some hard-water residue off the bottom of an ancient roaster which was not coated with enamel. The murky water infiltrated the pumpkin flesh, giving it a metallic tang and making it almost inedible. I labeled this batch for the German Shepherd dog, who seems to enjoy pumpkin, and ate it mixed with meats and other veggies.

Equipment Needed for Canning Winter Squashes

  • Pressure canner (not a regular pressure cooker designed for cooking only small amounts of food, without putting it in jars)
  • Large roaster (enamel preferred), or large pot for cooking squashes
  • Wooden spoon, for filling jars
  • Knives, for cutting squashes—one regular and one serrated
  • Ladle - optional, but good for "wet" squash types
  • Canning funnel (has a wide mouth)
  • Jar lifter
  • Tongs, for lifting lids
  • Saucepan or small cake pan, for scalding lids
  • Canning jars, quarts or pints (do not use regular "recycled" jars, which are of lower quality)
  • Canning lids of an appropriate size(s)
  • Vinegar (optional), for adding to canner water to avoid hard-water stains
  • Towel or large board on which to set cooling jars

Quick Reference for Canning Pumpkins/Squashes

  • Processing/Cooking time: 80 minutes (after 10 pounds pressure is built)
  • Pressure Setting: 10 pounds (may be 12 pounds at high elevations)
  • Overall time per full canner load: 3 to 4 hours (from filling jars to emptying cooled canner)
  • Jar Size: quarts, either wide or regular mouth; pints, either wide or regular mouth (wide mouth jars are easier to pack)
  • Storage term: 1+ years normally (depends on storage conditions, such as humidity)

Step 1: Wash and Prepare

  1. Wash the squashes or pumpkins with a nice scrubbing cloth and tap water. You may use a bit of soap if they are filthy; rinse thoroughly.
  2. Begin by cutting a slit in the pumpkin near the stem. You may have to stab hard. Make sure your knife is very sharp. Then cut around the stem, making a series of straight cuts, or whatever seems easiest. Be safe!
  3. Enlarge your slit and then switch to a serrated knife and cut to the bottom center of the pumpkin. Repeat at a different angle to cut neat wedges of golden pumpkin.
  4. The more wedges you cut, the harder it may be to hold your pumpkin still. Engage another pair of hands if necessary. Scrape seeds into a waiting bowl as you complete each slice, but don't bother yet with "strings."

Step 2: Cook Squashes and Pumpkins

  1. Place the squash in a roaster or bake the pumpkin. Bake until tender when pierced with a fork to the center. Large pumpkins or squashes are best baked in the largest roaster you can find, as they require 1 1/2 to 2 hours to become soft.
  2. Cool the squash or pumpkin at least an hour before handling, unless you like steam burns.
  3. To remove pulp from pumpkins, use your thumb to scrape small sections from the rind. Bits of rind in the pulp can be picked out later when you pack your jars.
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Step 3: Prepare Jars and Canning Equipment

  1. Wash (sterilize if necessary) and examine all jars (chips, cracks), rings (bent, excessive rust), and lids (misaligned rubber).
  2. Either gently simmer the lids (don't boil!), or set them in a small pan and pour on boiling water to cover to scald them.
  3. Pour into your pressure canner the recommended amount of water (usually 2 quarts) and begin heating it.
  4. Add a splash of vinegar to avoid hard water stains on your canner and jars.

Step 4: Pack Squash Pulp Into Jars

  1. Some squashes can be ladled into a canning funnel, others are better spooned in. Spaghetti squash ladles easily.
  2. Use a wooden spoon handle to help any thick parts go down. Fill to within 1/2" of the top.
  3. Pumpkin must be tamped down to remove air bubbles and to best fill each jar. Tamp it well when your jar is about half full, again when it is two-thirds full, and then spoon in more pulp to within 1/2" of top. Tamp again.
  4. Wipe the rim of each jar with a clean, damp cloth, then screw on lids firmly (but not tightly).

Step 5: Process Squash in a Pressure Canner

  1. Place jars in canner rack.
  2. Screw or fasten lid in place. On old-style canners, screw knobs down tightly in opposites, to achieve an even seal.
  3. Heat on low/medium heat until the steam vent is hissing and spitting, then wait 10 minutes to place the weight for 10 pounds pressure. Waiting ensures the canner is properly pressurized. Process 80 minutes, then turn off the heat and cool completely.

Step 6: Cool Pressure Canner and Jars; Store Jars

  1. Once the pressure gauge has returned to zero pounds, carefully remove the weight and lid of your canner. Unscrew knobs in opposites, just like you tightened them.
  2. Lift each jar out carefully with a jar lifter. If you have waited for the canner to cool sufficiently, you should be able to remove the jars promptly. Place jars on a towel away from drafts to cool overnight. Lids will "ping" as they cool and seal.
  3. When completely cool, check that all lids sealed properly (there should be no give), and then gently wash any residue off jars before storing in a cool place.

Puréed vs. Cubed Squash and Safety Concerns

In the comments at the end of this article, there is a discussion on the merits of cubing squash for canning, instead of puréeing it. The reasons are simple and scientifically sound: puréed squash does not heat up as well as cubed squash, nor as evenly. This means that while being canned, each jar of squash (especially in quarts) may not heat up sufficiently to the very center to kill all unlovely bacteria. This will, of course, invite spoilage of your product, and possibly illness for you and your loved ones.

I, personally, have never had a bad experience with puréed squash, but if the risks are ones you will not take, then by all means, cube your raw squash, pack it in jars, and fill to within a 1/2" of the rim with boiling water. Your squash will be soggy, but safe.

Winter Squash Varieties

Winter Squash Cooking Tips and a Recipe

Questions & Answers

Question: When cooking spaghetti squash with butter and brown sugar, is it okay to can?

Answer: Spaghetti squash should be great to pressure can like that! That sounds tasty. (There are no safety concerns that I can think of.)

© 2009 Joilene Rasmussen

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