Can commercial jars and lids be used for home canning?

canning jars

Re-usable Jars

Can commercial jars and lids be used for home canning?

 When I lived in the USA, I used Mason or Ball jars. My family had used them for generations. We re-used them year after year. As long as glass jars are in good condition they can be used again and again without compromise. If you are fortunate enough to have a collection of Mason or Ball jars, by all means use them. The Mason and Ball jar system for home canning is excellent. However, Mason jars have become quite expensive and if you are new to home canning, it can be a hefty investment to get started with Mason jars. However, you might be lucky enough to find some at second-hand shops, flea markets or yard sales. That said, let me take a moment to talk about jars and lids for the commercial food industry. Currently, two types of vacuum closures are widely used; the lug or twist cap (see picture) and the continuous thread lid, both with a Plastisol gasket. The lug has gained steadily in popularity to become the predominant vacuum-cap type. To seal a jar, the lug caps are secured to the glass finish. Steam builds up in the head space of the glass container between the cap and the contents of the jar. As the contents cool, a vacuum is created that seals the jar. The cap will show a concavity in appearance indicating the presence of a vacuum. It is desirable that the gasket be softened by heat to facilitate sealing. Both the lugs and vacuum hold the cap in place on the glass jar. Plastisol is a suspended resin in a plasticizer, with a product life of five years. Plasitsol lids are tailored to the product jar and process. For example, a closure intended for sealing a jelly jar may not be suitable on a pickle jar.

 Now to answer the question, “Can commercial jars and lids be re-used for home canning?”  In my humble opinion, “Yes, they can, with reservations.” In the Czech Republic the most popular system for home canning is a glass jar with a lug cap. When I came to the Czech Republic eight years ago, I spoke with a few women from my village and they assured me that they have been re-using commercial jars and lids with great success. If the jar is sterilized and the lug cap is heated in a pan of boiling water to soften the gasket, the jar will seal properly. When I empty the contents from a commercial jar,  I wash the jar and lug cap. Then I re-cap the jar and store it until it’s needed for canning. I categorize the jars; jelly jars, pickle jars, tomato sauce jars, etc.  When  I use them, I’m careful to fill them with the same type of contents as the jar’s previous use had been intended for.  By recapping them while in storage,  I don’t mix up the caps with a different type jar. I re-use a cap for only one time. I buy new lug caps, but continue using the glass jars year after year.

 Each year before canning, I bring out my capped jars from storage and examine each one. I hold it up to the light to search for any visible chips or cracks anywhere on the jar. Then I run my finger around the rim of the jar. If there are any rough places on the rim, I don’t use the jar. Even a micro chip on the rim will cause the jar not to seal properly. I examine the lug cap to see if it is scratched, rusted, or has any dents and check to see that the gasket is clean and in good condition. If the cap doesn’t meet all of these criteria, I throw it away and use a new cap. Then I run the jars and caps through the dishwasher on high heat or I wash them by hand and place them in a large pot of water and bring it to a gentle boil. After washing the caps, I place them into a pan of boiling water to soften the gasket before sealing the jars. I’ve been re-using commercial jars and caps for several years and I’m satisfied with the results. A couple of my friends who do not home can, save their jars for me. Each year they call to tell me they have a bag of jars. I happily go and retrieve the jars then return later with a ‘thank you gift’; a couple of jars of my favorite homemade preserves. 

If you are interested in learning more about canning and preserving food, check out the National Center for Home Food Preservation. 

In the general information about jars, they mention that mason jars are best but standard jars can be used.  The jars are thinner and may break if you use the heat method (emerging jars in boiling water after filling them).  From my experience this is true.  However for most of the canning I do, I don’t need to use the heat method.