Hi List, Our staff educator with the most experience in food preservation recently retired, or I would refer this conversation to her, however I’ve looked up this topic on the National Center for Home Food Preservation website (our “go-to” source for canning information) and this is what they say about reusing commercial jars:
Most commercial pint- and quart-size mayonnaise or salad dressing jars may be used with new two-piece lids for canning acid foods. However, you should expect more seal failures and jar breakage. These jars have a narrower sealing surface and are tempered less than Mason jars, and may be weakened by repeated contact with metal spoons or knives used in dispensing mayonnaise or salad dressing. Seemingly insignificant scratches in glass may cause cracking and breakage while processing jars in a canner. Mayonnaise-type jars are not recommended for use with foods to be processed in a pressure canner because of excessive jar breakage. Other commercial jars with mouths that cannot be sealed with two-piece canning lids are not recommended for use in canning any food at home. You may read more on this topic here: http://nchfp.uga.edu/how/general/recomm_jars_lids.html I hope this help explain the thinking behind our not including commercial product jars in the upcoming Canning Jar Swap. Best regards, Sandy Repp Marketing & Communications Cornell Cooperative Extension of Tompkins County From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, June 23, 2016 11:17 AM To: SUSTAINABLE_TOMPKINS-L Subject: [sustainable_tompkins-l] Re: [sustainable_tompkins-l] Re: [sustainable_tompkins-l] 6/24-6/27: Gardener’s Plastic Pot Swap AND Canning Jar Exchange I concur with you Joel. We canned 1,000+ quarts per year of about anything cannable in a jar, including in a lot of recycled mayo jars. And yes the main problem with mayo jars as I recall was their larger diameter. George Frantz Sent from my Huawei Mobile -------- Original Message -------- Subject: [sustainable_tompkins-l] Re: [sustainable_tompkins-l] 6/24-6/27: Gardener’s Plastic Pot Swap AND Canning Jar Exchange From: Sarah Gagnon To: Sustainability in Tompkins County CC: Well, since this was posted to the sustainability list, and since my protests to the folks at Cooperative Extension have been ignored, I would like to make the case here that there is no good reason not to use mayonnaise or sauce jars in canning. I have done so for years. Sauce jars are true canning jars. Many even say "Mason Jar" on the side. I think this reality is driven by a Federal rule allowing canning jars as acceptable vessels for commercial sauces. Many small producers use regular canning jars for their products. Many of these jars are pint and a half jars, which Cooperative Extension seems to regard as a deficiency. I like the in-between size for some products I put up. They are great when a quart is too big and a pint is too small. If they have a screw-on lid that can be replaced with a standard lid and band, they work fine. Ditto for mayonnaise jars. Since glass quart mayo jars are no longer manufactured, they are a diminishing resource. They have the advantage of being round, which is easier to empty and clean. 7 of them won't fit in a canner, though, due to a slightly greater diameter. They need to be mixed in with regular jars. I was told that mayo jars have thinner walls than regular canners. The two types weigh exactly the same, and the round shape of the mayo jars is inherently stronger. In my 40 years of canning, the incidence of broken jars is no greater for mayo than for regular jars. In short, mayo and sauce jars are sometimes superior to regular canning jars for some uses and are as good for almost all others. I commend Cooperative Extension for promoting reuse with this exchange, but I deplore the implicit promotion of replacement of mayo and sauce jars with regular canning jars. Joel On 6/23/2016 9:13 AM, Sandra J. Repp wrote: Gardener’s Plastic Pot Swap AND Canning Jar Exchange Friday, June 24-Monday, June 27, 9:00am-6:00pm Cornell Cooperative Extension of Tompkins County, 615 Willow Avenue, Ithaca NY LEAVE your plastic nursery pots, trays and cell packs IN GOOD CONDITION (no broken or torn plastic) in the designated area on the east side of the CCE Parking lot at 615 Willow Ave. Pots will be sorted by size, so help us out by putting them in the pile with similar sizes! TAKE AWAY as many pots as you can use, too! Plastic that is left after the event will be taken to a recycler for processing. Recycle your plastic plant containers instead of throwing them away. CANNING JAR SWAP! Canning jars must be empty, free of debris and in good condition (not broken). Please bring your canning jars to donate in BOXES, NOT BAGS! All size canning jars are welcomed, but they must be true canning jars (no mayonnaise or sauce jars, please). Take away as many jars as you can use! The purpose of the swap is to promote reuse of pots and jars. Gardeners and canners appreciate this opportunity for reusing pots and canning jars. After June 27th, no more pots or jars will be accepted at Cooperative Extension, however county residents can take these items to the Tompkins County Recycling/Solid Waste Center. For more information, call Cooperative Extension at 607-272-2292 or visit http://ccetompkins.org/events/2015/06/19/gardeners-pot-swap-recycling-event . For more information about sustainability in the Tompkins County area, please visit: http://www.sustainabletompkins.org/ If you have questions about this list please contact the list manager, Tom Shelley, at [email protected].
