As you know, store-bought cans contain some of our laziest and most guilty pleasures: pineapple slices, ravioli, beans, Spam.
But in American homes, where old-timers and neophytes alike labor to preserve their harvests, most of the "canning" is actually taking place with glass jars, not metal cans. Oddly, the go-to verb that describes the process largely remains "can."
But language, being dynamic, constantly evolves to keep pace with the changing meanings it conveys. Recently, I've noticed a new verb in circulation.
Overheard at a coffee shop: "Let's jar tomorrow after farmers market."
Via e-mail: "What are you jarring these days?"
At the farmers market: "They jarred on their first date."
This linguistic revolt reveals some of the energy and creativity being focused on home economics these days, and given that fresh force, it's worth revisiting the basics of packing food into jars. Because no matter what you opt to call it, doing it right remains as critical as ever. You don't want to seal an ill fate with those lids.
Talking shop on jarring carries liability concerns; it's possible to get quite sick and even die from poorly jarred food. So, let's try not to get hurt, or sued, shall we?
Jarring recognizes two primary categories of contents. High-acid foods, like fruits or pickles, are less susceptible to spoilage. Low-acid foods, like veggies not pickled in vinegar solution, or beans and meat, carry a higher risk of spoilage.
High-acid foods can be jarred in a water bath — simply a pot of boiling water into which sealed jars of food are submerged. Any pot that holds enough water will suffice, but most people use a specialized five- or eight-gallon enameled kettle.
Low-acid foods have to be jarred in a specialized pressure cooker called a "pressure canner" (ranging in cost from $20 to $350 on amazon.com). Unlike the pressure cookers used for cooking, pressure canners have gauges that measure their interior pressure in pounds per square inch. Different foods have to be pressure-jarred for different amounts of time, and both time and pressure requirements increase with elevation. Follow recipes and cooker manuals and you'll do fine.
As for those recipes, ideas for pretty much anything you could want to put in jars, including condiments, juice and ready-to-eat meals, can be found for free online.
A jarring package, in addition to the jar, contains the lid, which itself contains a rubberized ring that seals against the rim of the jar, and another ring, to be screwed onto the jar's threaded neck to hold the lid in place. Jars and rings can be re-used, but lids should only be used once. (A box of 10 new lids costs about $2.)
Jars must be squeaky clean and free of cracks, with unblemished rims. It's best to use jars intended for jarring, aka Mason jars, like the Ball or Kerr brands, though many people reuse mayonnaise or pasta sauce jars. While canning rings and lids will fit many such jars, the glass from which they're made isn't necessarily up to the temperatures and pressures of jarring. Some reused grocery jars may break in the process, turning the water bath or pressure cooker into a soupy sea of wasted produce. Mason jars, though stronger, also can crack.
To avoid this, keep the jars and their contents as warm as possible prior to lowering the jars slowly into the boiling water with a pair of canning tongs. Sterilize lids and jars before use. The jars can be boiled, steamed or baked at 220 degrees. Sterilize lids in a pot of water, bringing the water to the pre-boiling point where little bubbles start to float up, then removing the heat before the water boils. Leave sterilized lids in the hot water, covered, until use.
Once your jars are sterilized and ready for filling, a common mistake is to overpack them. The term "headspace" refers to the empty space between the top of the food and lid. Without enough, there won't be adequate air to contract as the jar cools, and the lid might not seal. So leave a good inch between the food and the point where the rounded glass of the jar joins the vertical, threaded neck.
After removing the finished jars from the pressure cooker or water bath, set them aside to cool. If you did it right, you'll be serenaded by a chorus of "pings" as your jars seal, one by one.
Store your sealed, labeled and dated jars in a cool place and inspect each jar before and after opening. Look for bulging lids, discolored contents, contents that bubble upon opening, escaping gas upon opening and off odors. Toss the jar's contents at any suspicious sign.
Lastly, after enjoying your salsa with breakfast, pickles with your sandwiches and pie filling for dessert, noticeably slip the word "jar" into conversation somewhere. Never mind the puzzled looks.
Ari LeVaux writes Flash in the Pan, a syndicated weekly food column. Visit flashinthepan.net for more food tips.
Canning | Jarring