The Problem With Mason Jars

2023-02-28 14:26:12 By : Ms. Yoyo Xu

Katherine Martinko is an expert in sustainable living. She holds a degree in English Literature and History from the University of Toronto.

The Mason jar is a mainstay in every zero-waste, plastic-free, home-cooking, tree-hugging household these days. Beloved by hipsters for mixing cocktails and schlepping cappuccinos, by home canners for preserving garden produce, by DIYers and Pinterest fans for organizing and decorating, the Mason jar truly is a celebrity workhorse of the 21st century.

Despite its seemingly limitless abilities, however, the Mason jar does have some downsides, as pointed out by Life Without Plastic in a recent newsletter.

First, you know that white undercoating on the lids? It contains a chemical called bisphenol A (BPA), or, where advertised as BPA-free, a substitute called BPS. This coating, while meant to be protective, is not entirely safe. These chemicals are known hormone disruptors that leach into food that comes into contact with it, and even the BPA substitutes are not viewed favorably. You can read more about the concerns surrounding BPA and BPS in a report published by the Environmental Working Group.

Second, the screw-top ring is made of tin-plated steel that is not water-resistant and, therefore, prone to rust if it comes into contact with moisture or food. This seems a rather poor design for a jar that’s often used to carry liquids.

The good news is, there are alternatives out there. Yes, you heard that right — it’s possible to improve upon the exalted Mason jar. Here are some suggestions.

It is possible to buy stainless steels lids and screw bands to avoid rusting. That way, you don’t have to replace your collection of jars. Life Without Plastic writes:

“These lids are made from high quality 304 stainless steel with a food-grade silicone gasket attached to the lid. This gasket helps to preserve your food better as they create a tighter seal. However, these lids are not to be used for canning because they do not pop. Instead use them for bulk shopping, takeout or leftover storage.”

These beautiful jars come with bamboo lids and silicone rings that give a good seal — not entirely leakproof, but fine for transporting thicker foods, or storing in the fridge. The lid should be removed if the jar is put in the microwave. They come in two sizes — 18 and 10 ounces.

Weck jars are a popular alternative to Mason jars, made in Germany with glass lids and rubber sealing rings. They can be used for canning, although this method is not approved by the USDA. (This does not mean it’s dangerous, but simply that “there has never been a study funded and performed by the USDA or extension service on these jars," via Living Homegrown.) The jars are attractively shaped, come in multiple sizes, and have a lid that’s held on by stainless steel clips.

Made in France, these pretty jars are similar to Weck in that they have glass lids and rubber seals, but the lids are held on permanently with a metal hinge and clasp, so no missing pieces. They come in a range of sizes, and are the favorite of zero-waste queen Bea Johnson.

Tattler is a U.S. company that makes hard plastic reusable canning lids with rubber (latex-free) seals. Using these eliminates the issue with BPA, but you still use a metal screw band to hold it in place. According to A Gardener’s Table, the plastic is made from “a substance called acetal copolymer. This plastic contains no BPA, and it’s approved by the USDA and FDA for contact with food, including meat, provided the food doesn’t contain 15 percent or more alcohol.” The company has a lifetime guarantee.

These jars have been made in Italy since the 1970s and feature a single-piece, screw-on lid that’s entirely BPA-free. They’re easy to use: fill a sterilized jar, screw on the lid, and process in boiling water. You can tell it’s been processed when the center is pulled down and they’re easy to open by unscrewing; however, it's important to note that this kind of canning is not officially approved by the USDA. The English translation of the manufacturer Bormioli Rocco’s website does not contain nearly as much information as the Italian version.

Moon, Min Kyong. Concern about the Safety of Bisphenol A Substitutes. Diabetes Metab J, 2019, vol. 43, pp. 46-48.,  doi:10.4093/dmj.2019.0027

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