When my mother offered me my grandmother’s pressure cooker a couple of years ago, I only agreed to take it because it meant I could reclaim my freezer from the stockpile of chicken stock it had become. Unlike jams or even tomatoes, you can’t can meats or stocks in a water bath. Instead, you need the high temperature environment of a pressure cooker. You can, of course, just freeze it, but then you have to remember to remove it at least a day ahead of time, and I always forget. Hence, the need to can.
Step 1: Make the Stock
Don’t be intimidated by stock: it is, after all, the basis of peasant cooking everywhere. All you really need is either a chicken or a chicken carcass and some aromatics. Carrots, celery, onions, garlic, and parsley are traditional, but you can use cilantro, tomatoes, peppercorns, turnips, ginger, or anything else that tastes good boiled. Don’t add anything that gets bitter or otherwise nasty as it boils, like cabbage, broccoli, or eggplant.
Just toss your odds and ends into a pot, add a few quarts of water, and let it cook for awhile. If you’re using a regular stovetop pot, you should probably let it simmer about an hour. Since I tend to make my stock with leftover bones, I like to use the pressure cooker to extract as much flavor as possible: 12 minutes at 15 pounds pressure. Next, strain the liquid and let it cool for several hours or even overnight. The fat will form a solid layer (see right) that you can skim off, if desired.
Step 2: Can the Stock
I know, I know: this is where people get nervous—and rightly so. Canning low-acid foods can be a dangerous business, but it’s perfectly safe if you follow a few simple steps.
1. Heat up the stock, and use clean jars. Start with clean, sterilized jars. Garden variety commercial jars may not be strong enough to stand up to the temperature and pressure of canning. For this, you want real Mason jars. Meanwhile, heat the stock to near boiling.
2. Heat the lids. While you can reuse the rings, it’s important that you use new lids every time you can. This is because the rubber ring on the lid is not guaranteed to work more than once. It might, but is the risk of botulism worth it? Spend the $1.99 and buy yourself another dozen lids. Soften the rubber and sterilize the lids by heating (but not boiling) them for about 10 minutes.
3. Transfer the stock to the jars, and screw on the lids. You can buy a canning funnel designed especially for regular-mouth jars—it’s totally worth it. For pressure canning, you should leave 1″ headspace. The lids should be screwed on fairly tight.
4. Transfer the jars to the pressure canner. A large pressure canner, like one pictured here, can hold up to 7 quart jars. Be sure to use the rack so the jars don’t break. Next, add 2 quarts of boiling water to the canner. A note to experienced water-bath canners: it is NOT necessary to cover the jars! You just need 2 quarts or so to produce enough steam to raise the pressure to the proper temperature.
5. Seal the canner and evacuate the steam. This is an easily overlooked, but important, step. Close and lock the lid and turn on the heat to high, but don’t add the pressure regulator yet. After a few minutes, you’ll see a jet of steam coming out of the central valve.
It’s a little hard to see in this picture, but trust me, it’s there. Let it go for about 7 minutes, then add the pressure regulator.
6. Cook at pressure. Most canning guides suggest 25 minutes at 10 pounds of pressure for quart jars, and 20 minutes for pint jars.
7. Let the pressure drop of its own accord. Then wait another hour or so before opening the canner. Even at this point, the contents of the jars may still be shockingly hot, so be very careful before reaching in there. You’ll want to use tongs or potholders to remove the jars from the canner.
8. Cool and store. This is the easy part! Let the jars cool completely, label, and store in a dark place. Do make sure that they’ve sealed: if the lids are springy, they didn’t, and you should refrigerate or freeze them instead. But honestly, with pressure canning, everything seals, every time.