Gardening is a deeply satisfying activity. There is something innately appealing in planting seeds, nurturing them to maturity and feeding your family with the product of your own efforts. Unfortunately, as your carefully-tended plants reach full production, you may find that you've grown significantly more than you can reasonably use. Putting some away for winter is the obvious answer. Freezing string beans, for example, is fast and easy but does require a little bit of preparation.
Cooking vs. Blanching
Putting string beans in a pressure canner results in jars of fully cooked beans, much like the canned beans from your supermarket. Freezing allows you to preserve a fresher flavor and better texture, and you don't need to cook your beans to do it. However, it is important to par-cook your beans slightly in a process called blanching and shocking. This deactivates natural enzymes in your beans that will make them deteriorate and spoil, even in the freezer. It also improves the beans' color and kills any mold spores or bacteria that might be present.
Blanching and Shocking
Begin by boiling a large pot of water. Add 1/4 cup of salt to the water for each gallon of water, which will help the vegetables maintain their color. Place a large bowl of ice water nearby. Wash your beans and remove any stray leaves or other garden debris. Drop the beans into the boiling water in small handfuls, so the water stays boiling. Boil the beans for three minutes, which is the recommended blanching time. Remove them to the bowl of ice water -- a process called shocking -- to stop the cooking. Drain well before freezing.
If you own a large steamer, or a large pot with a steamer insert, you can use that to blanch your beans. Steaming the beans takes approximately 50 percent longer but you can cook more of them in each batch, so it is at least as efficient as boiling and sometimes more so. Fill your steamer with beans and water to their respective fill lines, and start it. For string beans, your blanching time will be approximately 4 1/2 to 5 minutes. Shock them in ice water after blanching.
In the hurry of the harvest season you may be tempted to process and freeze your beans with as little fuss as possible, but it's worth taking a moment to consider your options. Experienced gardeners and cooks try to package the beans exactly as they'll be used, which means trimming the ends, cutting them to size or perhaps even julienning or "Frenching" them. Heirloom varieties will still have the tough strings that need to be removed before cooking. Doing these things during harvest takes extra time, but will make the beans quicker and easier to cook with later on.