In many households, harvest season means canning season. Preserving the bounty for months to come is a time-honoured procedure, but recently Jarden, the company that manufactures Ball and Bernardin canning jars and lids, casually mentioned that they had completely changed their recommendations for how to use their canning jar lids.
This set off a small firestorm on the internet, because the new information did not match what was written on most current jar and lid packaging and because customers calling the customer service hotline were getting slightly different information.
A conference call with Jarden cleared up the facts. This post, written by canning expert Theresa Loe and originally posted on her blog Living Homegrown, reflects the official, company-wide messaging on the new options for preparing Ball and Bernardin canning lids and the reasoning behind it.
The old recommendation:
Canners know that the recommendation has always been to drop the canning lids (the round discs that sit on top of glass jars to form a seal) into a pan of simmering or boiling water while you prepare your recipe. The purpose of the hot water was to soften the rubber gasket and make for a good seal.
The new recommendation:
Jarden now says heating the lids before canning is not necessary. Instead, simply washing the lids and using them at room temperature, or heating them in water no warmer than 180 degrees is sufficient.
Why the change?
Originally Jarden hotline representatives said the change was due to a new, BPA-free coating on the lids. We have since been told this is not the case. Jarden says they simply tested the process and determined that heating in warm water or not heating at all will get the same results.
However, if the lid is overheated in boiling water, it can cause the plastisol coating to thin out. If that happens, you may get a poor seal that fails later on the pantry shelf, or no seal at all.
Why don’t the box instructions reflect this?
Many boxes on the market still have the old instructions. Jarden says the updated information has already been printed on this year’s boxes but it takes time for this to trickle down through the supply chain on to store shelves.
So either way is okay?
Yes, gently heat or don’t heat at all. The choice is yours. But just don’t overheat the lids before using.
What about sterilizing the lid?
We all know the USDA recommends any recipe processed in a water bath less than 10 minutes must have the jars, rings and lids sterilized.
Jarden’s response is to make sure to process preserves for 10 minutes or longer in a water bath to take care of sterilizing. (All pressure-canned products are automatically sterilized during the processing time in the pressure canner)
This discussion brings up the whole topic of what plastic formula is used as the coating replacement for BPA (Jarden won’t say exactly, as it is proprietary). Is it worse than BPA or does it matter? That topic was discussed over here a few years ago.
Which lids are BPA-free?
The BPA-free change happened around 2013. All the lids manufactured last year were BPA-free, but many stores were still selling out the old stock. Last year’s box only said “Made in USA” and did not make any distinction about being BPA-free.
According to Jarden, if you find any of the following markings, your lid is BPA-free:
- Says “Made in USA” on the box
- Has an American flag on the box
- Says “BPA-free” on the box
- Says “Made in USA” on the lid
So even if your box is missing, you can tell your lid is BPA-free because it will say “Made in USA.”
Also note that if you have really old lids (5 years or more), the rubber seal loses elasticity with time and may not seal as well. Use old lids for freezing things like soup.
What about other brands?
There have been no changes in other canning lid brands. Each manufacturer of jar lids has their own recommendation and procedures for using the lids. Always read the box and follow the instructions for best results.
But note that Jarden is the largest maker of jars and lids in North America. So most of the lids you buy would follow this new procedure.
What if I forget and overheat the lids?
No worries. The canning police will not come write you up. The worst that can happen is that you get some seal failures.
What about pressure canners?
Many canners are wondering: If over heating thins the plastisol gasket on the lid, what happens when it reaches over 240 degrees of a pressure canner?
The experts at Jarden say that overheating in a pan of water will cause the plastisol to “thin,” which means it spreads out on the lid’s surface and flattens out too much. However, when that heat comes in a pressure canner, the plastisol is already up against the glass jar rim. They say they have found that the extreme heat just causes it to spread around the glass rim (as you hope it would) and gives a good seal.
The difference is that in the saucepan of water, the plastisol has no place to go but out across the lid. In a pressure canner, it spreads around all sides of the glass rim, giving a good seal.