Green or Green

• Hard, immature green tomatoes are a fact of life for any gardener who plants a few vines. In the warm South, where tomatoes will produce for months on end, harvesting the green fruit is a pragmatic way to get several month's food from a plant. In more northern climes, much of your crop might still be green when the season comes to an end. In either case, the unripe tomatoes are firm and acidic, well suited to canning. A few heirloom and hybrid varieties are green even when fully ripe, and shouldn't be used for frying. Like fully ripe red tomatoes, they'll turn to mush in your skillet.

Water-Bath Canning

• Green tomatoes are fried with their skin on, so they don't require much preparation before you can them. Discard any tomatoes that are moldy, cracked or show visible signs of insect damage. Wash them carefully under cold, running water, then cut out the cores and slice the tomatoes. Roughly 1/4 inch is a common thickness for frying, though you can slice them thicker, if you prefer. Pack the tomato slices into sterile canning jars, and cover them with boiling water. Run a knife around the jar to free any bubbles, then cover them finger-tight with new lids. Simmer pint jars for 40 minutes and quart jars for 45, then cool them for storage.

Pressure Canning

• Green tomatoes are more acidic than ripe tomatoes and don't require any added lemon juice, vinegar or citric acid to remain food safe. Still, if you have a pressure canner, you might opt to use that instead of a water bath. The faster, higher-temperature processing means pressure-canned green tomatoes will maintain their quality and fresh flavor for longer. Pint jars can be canned at low pressure, just 6 psi at sea level, for 15 minutes. Larger quart jars require 10 psi, but only 10 minutes of processing time.

Using the Green Tomatoes

• After you've checked your jars for a good seal, store them in your pantry or another cool, well-ventilated place where they'll be protected from direct light. To use them, unseal a jar and either drain it or remove the number of slices you'll need. Follow the usual three-step process of dredging the tomatoes in flour, then dipping them in beaten egg and finally in breadcrumbs or -- more traditionally -- cornmeal. Cook the tomatoes in a heavy skillet at medium heat, ideally in no more than 1/4 inch of oil.