Mason jars have become something of an obsession for me lately.

It all started when my friend Stef turned me on to using them as drinking glasses. She’d taken to a local brand of kombucha that came in a Mason jar and stocked up quite a collection. I was surprised how nice they were to drink from.

Then I found a box of them up in a closet, right around the time I’d decided to make candied nut mixes for holiday gifts. They’re airtight, reusable, don’t absorb anything, and had the added benefit of showing off the beautiful nut mixes. With a ribbon tied around the top, they made the perfect package.

Enter canning season, where these guys really get their glory. All of a sudden we’ve got jams, pickles, oils and vinegars, salsas, soups, and dried herbs all packed up in Mason jars. Most come with measuring marks on the sides, which make them even handier for mixing and processing.

I’ve also used them for cut flowers and to store fresh onions, leeks, and greens in water. They also make great storage for grains, beans, flours, and nuts. You can freeze in them, make salad dressings in them, even use them to roll dough or pack lunches. I spotted one of my herb school classmates eating a salad out of one during last weekend’s campout. I was eating trail mix out of mine.

The name “Mason jar” is really an umbrella term for screw-lid glass jars that come in a variety of sizes from 4 ounces to a half-gallon. Their lids consist of a metal band, which fits into the grooves around the jar’s opening, and a flat, circular piece that is held in place by the band.

The disc has a ring of rubber on its underside, which, when heated, is what creates the hermetic seal needed to safely store canned goods (and causes that distinctive “popping” sound when you open it up).

They’re also called canning jars, fruit jars, or Ball jars, after one of the big manufacturers. Both Ball and Kerr, the main American brands, are actually part of the same corporation these days.

Much like ramekins, I can never seem to get enough of these things. Just when I think I’ve built up a good supply, I end up filling them up, giving them away, or using them at herb school, where they’re integral in making many of our medicinal preparations. The longer I keep them around, the more ways I find to use them.

I’ve discovered that it can be tricky to track down a good retailer for Mason jars. They’re much more visible and widely available right now, as canning is at its height, but generally you have to do some hunting. Check out hardware stores, garden stores, and outdoor/hunting surpluses. I found some at my local grocery store recently, but they tend to be spottier there.

You shouldn’t pay more than a dollar apiece for Mason jars. Brand new sets of 12 run about $8-12, depending on the size. You can also get them in a wide-mouthed variety, which is big enough to fit an emulsion blender into. When using that hermetic seal, it’s important to discard and replace the discs, which you can buy a box of on their own. The bands are reusable.