Press "Enter" to skip to content

UMaine Cooperative Extension Teaches Pressure Canning

With fall approaching quickly, there is a lot of last minute farm and garden work to be done in Maine. As the summer winds down, many crops are ready to be harvested and some may wonder what to do with an abundance of produce. Thankfully, the University of Maine Cooperative Extension has helpful advice about how to pressure cook excess vegetables from the garden. 

Lisa Fishman began the webinar with a quick introduction of the UMaine Cooperative Extension and read an affirmative action and equal opportunity employer statement. She then posed the following poll question: “Which of the following requires processing in a pressure canner?” Participants could select an answer of jams, tomatoes, green beans or applesauce. Fishman explained that green beans are the correct answer because they are a low acid food. Low acid foods must be canned under pressure because they carry c. bot, a bacteria that can lead to serious or fatal food poisoning if not eradicated at a high temperature. 

“The pressure canner is a little bit different than the water bath canner,” Fishman said.“The combination of steam and pressure [in pressure canning] allows it to hit 240-260 degrees Fahrenheit.” Because water bath canning relies on boiling water and not the buildup of steam, the water bath canning method can only heat food to 212 degrees Fahrenheit. 

The presentation then turned to Kate McCardy, who demonstrated how to make homemade tomato sauce with a pressure canner. She reviewed the parts of the canner and used a 16 quart stovetop pressure canner in this presentation. She pointed out specific safety mechanisms like a rack which sits at the bottom of the pot to prevent glass breaking and the locking lid that ensures users don’t open the pot while the contents are under pressure. There is also a gasket which seals the pot closed and keeps the steam inside. It’s important to check the gasket prior to each use to ensure it’s not melted from overuse and that it will still create a seal. 

McCardy went on to share her spaghetti sauce recipe which uses thirty pounds of tomatoes processed through a food mill, one cup of onions, a clove of garlic, one cup of celery, salt, dried spices, sugar and vegetable oil. For different flavors, peppers or mushrooms can be substituted for the one cup of celery. 

McCardy used tongs to handle clean jars so she could fill them with the sauce. 

“My spaghetti sauce gets paddled into the jar and we are going to leave 1 inch of headspace … when you are pressure canning your headspace is one inch usually,” says McCardy. 

Headspace is the amount of room between the sauce and the rim of the jar. Having some space ensures the jar won’t be overpressurized. McCardy finished making the sauce and turned the conversation back over to Fishman. 

Fishman shared more information about canning and left space for questions and answers. 

Next month, the UMaine Cooperative Extension will be hosting a class on fermenting vegetables. This class will be available from noon to 12:45 p.m. on Oct. 12.

Get the Maine Campus' weekly highlights right to your inbox!
Email address
First Name
Last Name
Secure and Spam free...