Asparagus is a low-acid food and must be pressure canned to kill harmful bacteria. You cannot use a waterbath canner for this recipe. I bought a fantastic and reliable Presto pressure canner on Amazon for under $100 and love it.
Preservation method: Pressure canning
Difficulty Level: Moderate
Asparagus (Pressure Canning)
3 1/2 lbs (or about 70 spears) asparagus
Boiling water or broth
Salt, if desired (1/2 tsp per pint, 1 tsp per quart)
Wash asparagus and drain. Remove tough ends and cut to fit into jars. I like Weck’s jars made for asparagus that I bought at Williams Sonoma. Leave a generous 1″ headspace in jar. Add salt if using.
Tightly pack asparagus into hot jars without crushing. During processing, the asparagus will shrink and soften which may result in a final product that is less full than you are expecting. Pack as snugly as possible.
Ladle boiling water or broth into jars to cover vegetables, leaving 1″ headspace. Remove air bubbles with a wooden skewer and readjust headspace leaving 1″.
Wipe rims, center lids onto jars. Screw bands down to fingertip tight.
Place jars into pressure canner. Adjust water level according to manufacturer’s directions. Lock lid and bring to boil over medium-high heat. Vent steam for 10 minutes, then close vent. Continue heating to achieve 10 lbs of pressure. Maintain pressure for 30 minutes pint jars or 40 minutes quart jars. If pressure drops below 10 lbs of pressure during processing, bring pressure up to 10 lbs again and start timer at zero – counting down 40 minutes once more.
Turn off heat. Let pressure turn to zero naturally. Wait two minutes longer and then open vent. Remove canner lid. Wait 10 minutes and then remove jars. Cool completely and allow jars’ to seal overnight. Date and store in pantry up to one year.