Canned Vegetable Broth

Ingredients

Instructions

1. 1Understand before you begin that even a plain vegetable broth without any meat must be treated as a low-acid liquid of uncertain, unmeasured pH, so it must be processed in a pressure canner just like a meat broth; a boiling-water bath is not safe for this recipe, even though it seems like a simple vegetable product.
2. 2Wash 7 quart jars in hot soapy water or a dishwasher and keep them hot; wash new lids and prepare them exactly as the manufacturer directs.
3. 3Combine the onions, carrots, celery, garlic, mushrooms, and parsley stems in a large stockpot with the water, bring to a boil, then reduce the heat and simmer, partially covered, for about 1 hour to extract flavor from the vegetables.
4. 4Strain the broth through a fine-mesh strainer or cheesecloth into a clean pot, pressing gently on the solids to extract liquid, then discard the solids.
5. 5Bring the strained broth back to a full rolling boil so it is hot when you fill the jars.
6. 6Ladle the boiling broth into the hot jars, leaving 1 inch of headspace, and add salt only if desired for flavor.
7. 7Run a bubble tool around the inside of each jar to release any trapped air, then recheck and adjust the headspace to 1 inch if it has changed.
8. 8Wipe the jar rims clean of any residue, center a lid on each jar, and screw the band down fingertip tight.
9. 9Load the jars into the pressure canner, add water as directed by the manufacturer, lock the lid, and vent steam steadily for 10 minutes before pressurizing.
10. 10Process pint jars for 20 minutes and quart jars for 25 minutes at 10 pounds pressure in a weighted-gauge canner up to 1,000 feet (15 pounds above 1,000 feet), or 11 pounds in a dial-gauge canner up to 2,000 feet (12 pounds from 2,001 to 4,000 feet, 13 pounds from 4,001 to 6,000 feet, 14 pounds from 6,001 to 8,000 feet).
11. 11Turn off the heat once the time is up and let the canner depressurize naturally on its own; never quick-release, even for a vegetable-only broth.
12. 12Wait until the gauge reads zero, then wait 2 more minutes, slowly vent any last pressure, wait 10 more minutes, then unlock and open the canner.
13. 13Move the jars to a towel-lined surface and let them cool undisturbed for 12 to 24 hours.
14. 14Check that each lid has sealed, wipe the jars, label with contents and date, and store in a cool, dark place for up to about 1 year.
15. 15Before using, boil the broth hard for 10 minutes to destroy any possible botulinum toxin, and discard without tasting any jar with an off smell, spurting liquid, or an unsealed or bulging lid.