1. Produce
  2. Vegetables
  3. Squash-Summer
  4. Canning

Canning Squash-Summer

1. Selection

SAFETY NOTE: Because summer squash is a low-acid food and there is no research verifying a safe home processing time or method, summer squash can only be safely canned as an ingredient within a high-acid, tested recipe such as 'Tomatoes with Zucchini or Okra.'  

  • For every 3 pounds of tomatoes, use up to 1 pound of okra or zucchini.
  • Refer to the recipes below for instructions and proper processing techniques to safeguard against spoilage, mold, and bacterial contamination.

Recipes

If this is your first time canning or it has been awhile, it is recommended that you read Using Pressure Canners and General Canning Information before beginning. 

2. Ingredients

  • Tomatoes (An average of 23 pounds is needed per canner load of 7 quarts, or an average of 14 pounds per canner load of 9 pints.)
  • Zucchini or Okra  (Use an average 1 pound of zucchini or okra for every 3 pounds of tomatoes.)
  • Pearl onions (4-5) or Onion slices (2) per jar--optional
  • Canning and pickling salt, if desired (up to 1/2 teaspoon/pint or 1 teaspoon/quart)

3. Equipment

  • Pressure canner: A specially-made heavy pot with a rack and a lid that can be closed tightly to prevent steam from escaping. The lid is fitted with a vent (or petcock), a dial or weighted pressure gauge and built-in safety features. It must be large enough to hold at least four quart-size jars.
  • Canning jars: Use standard canning jars without cracks or chips (see recipe for sizes)
  • Lids and bands: Bands can be reused if they are in good shape, but lids must be new to ensure a proper seal
  • Long-handled spoon
  • Bowl
  • Colander (for draining fruit)
  • Wide-mouth funnel
  • Jar lifter for removing hot jars from the canner
  • Lid wand (magnetic tool used to transfer lids to jars)
  • Bubble freer, or a plastic or rubber knife-like utensil (for removing air from food)
  • Ruler for measuring headspace (some bubble freers include this feature)
  • Large cooking pot 
  • Medium pot for extra boiling water
  • Towels or wire rack for cooling jars
  • Paper towels
  • Hot pads
  • Cutting board
  • Knives
  • Food thermometer for measuring temperature of processing water 
  • Timer or clock

4. Prepare Canning Equipment

Pressure Canner-

  • Assemble and wash equipment and containers.
    • Wash canning jars in soapy water, rinse, and keep hot. (This can be done in a dishwasher or by placing jars in the water that is heating in your canner.)
  • Follow manufacturer’s instructions for preparing lids.
  • Put the rack and hot water into the canner. If the amount of water is not specified for a given food, use enough water so it is 2 to 3 inches high in the canner. (Always follow the directions with USDA processes for specific foods if they require more water be added to the canner.)
    • For hot packed foods, you can bring the water to 180 degrees F. ahead of time, but be careful not to boil the water or heat it long enough for the depth to decrease.
  • Begin preparing food for your jars while this water is preheating.

5. Prepare Ingredients

  • Wash tomatoes.
  • Dip tomatoes in boiling water 30 to 60 seconds or until skins split.
  • Dip in cold water, slip off skins and remove cores, and quarter.
  • Wash okra and/or zucchini, trim away stem end, and slice into 1-inch slices or cubes. 
  • In a large pot, bring tomatoes to a boil and simmer 10 minutes.
  • Add okra or zucchini and boil gently 5 minutes. 

6. Pack Jars

  • Add 1/2 teaspoon salt/pint or 1 teaspoon salt/quart to each jar, if desired.
  • You may also add 4-5 washed and peeled pearl onions or two onion slices to each jar.
  • Fill jars with hot vegetable mixture, leaving 1-inch headspace.
  • Remove air bubbles.
  • Add more tomatoes, vegetables or juices if needed, for 1-inch headspace.
  • Wipe rims with clean wet paper towel.
  • Adjust lids following manufacturer's directions.

7. Process Jars

Note: Using a boiling water bath canner is NOT recommended for this recipe.

Pressure Canner-

  • Place filled jars, fitted with lids and ring bands, on the jar rack in the canner, using a jar lifter. When moving jars with a jar lifter, make sure the jar lifter is securely positioned below the neck of the jar (below the ring band of the lid). Keep the jar upright at all times since tilting the jar can cause food to spill into the sealing area of the lid.
  • Fasten the canner lid securely. Leave the weight off the vent pipe or open the petcock.
  • Turn the heat setting to its highest position. Heat until the water boils and steam flows freely in a funnel-shape from the open vent pipe or petcock. While maintaining the high heat setting, let the steam flow (exhaust) continuously for 10 minutes.
  • After this venting, or exhausting, of the canner, place the counterweight or weighted gauge on the vent pipe, or close the petcock. The canner will pressurize during the next 3 to 10 minutes.
  • Refer to the tables below for the correct pressure and processing times for your elevation, gauge type and jar size. 
  • Start timing the canning process when the pressure reading on the dial gauge indicates that the recommended pressure for your elevation has been reached, or when the weighted gauge begins to jiggle or rock.
    • One type of weighted gauge should jiggle a certain number of times per minute, while another type should rock slowly throughout the process – check the manufacturer’s directions!
  • Regulate heat under the canner to maintain a steady pressure at or slightly above the correct gauge pressure.

IMPORTANT: If at any time pressure goes below the recommended amount, bring the canner back to pressure and begin the timing of the process over, from the beginning (using the total original process time). This is important for the safety of the food because loss of pressure at any time can result in underprocessing, or unsafe food and quick and large pressure variations during processing may cause unnecessary liquid losses from jars.

  • When the timed process is completed, turn off the heat, remove the canner from the heat (electric burner) if possible, and let the canner cool down naturally. (Lift the canner to move it; do not slide the canner. It is also okay to leave the canner in place after you have turned off the burner. It is better to do so than to let jars inside the canner tilt or tip over if the canner is too heavy to move easily.)
  • While the canner is cooling, it is also de-pressurizing. Do not force cool the canner. Forced cooling may result in food spoilage.Cooling the canner with cold running water or opening the vent pipe before the canner is fully depressurized are types of forced cooling. They will also cause loss of liquid from jars and seal failures. Forced cooling may also warp the canner lid.
  • Even after a dial gauge canner has cooled until the dial reads zero pounds pressure, be cautious in removing the weight from the vent pipe. Tilt the weight slightly to make sure no steam escapes before pulling it all the way off. Newer canners will also have a cover lock in the lid or handle that must release after cooling before the lids are twisted off. Do not force the lid open if the cover locks are not released. Manufacturers will provide more detailed instructions for particular models.
  • Depressurization of older canner models without dial gauges should be timed. Standard size heavy-walled canners require about 30 minutes when loaded with pints and 45 minutes when loaded with quarts. Newer thin-walled canners cool more rapidly and are equipped with vent locks that are designed to open when the pressure is gone. These canners are depressurized when the piston in the vent lock drops to a normal position. Some of these locks are hidden in handles and cannot be seen; however, the lid will not turn open until the lock is released.
  • After the canner is completely depressurized, remove the weight from the vent pipe or open the petcock. Wait 10 minutes; then unfasten the lid and remove it carefully. Lift the lid with the underside away from you so that the steam coming out of the canner does not burn your face.
  • Using a jar lifter, remove the jars one at a time, being careful not to tilt the jars. Carefully place them directly onto a towel or cake cooling rack, leaving at least one inch of space between the jars during cooling. Avoid placing the jars on a cold surface or in a cold draft.
  • Let the jars sit undisturbed while they cool, from 12 to 24 hours. Do not tighten ring bands on the lids or push down on the center of the flat metal lid until the jar is completely cooled.
  • Once cool, remove the screw bands and check the seal. If any jars did not seal, treat the food as 'fresh' by:
    • Eating the food immediately
    • Refrigerating for use within a week
    • Freezing
    • Recanning (If recanned, you must repeat the entire process.)

8. Store

  • Store in a cool, dark place, where there is no danger of freezing.
  • Stored properly, canned tomatoes and vegetables should retain their quality for about 1 year.

Not sure of your elevation? Click here

Weighted gauge pressure canner-Process PINTS for 30 minutes
0-1,000 ft 1,001-10,000 ft
10 lbs 15 lbs
Weighted gauge pressure canner-Process QUARTS for 35 minutes
0-1,000 ft 1,001-10,000 ft
10 lbs 15 lbs
Dial gauge pressure canner-Process PINTS for 30 minutes
0-2,000 ft 2,001-4,000 ft 4,001-6,000 ft 6,001-8,000 ft 8,001-10,000 ft
11 lbs 12 lbs 13 lbs 14 lbs 15 lbs
Dial gauge pressure canner-Process QUARTS for 35 minutes
0-2,000 ft 2,001-4,000 ft 4,001-6,000 ft 6,001-8,000 ft 8,001-10,000 ft
11 lbs 12 lbs 13 lbs 14 lbs 15 lbs
Boiling water bath processing time-PINTS and QUARTS
0-10,000 ft
Not recommended