Prepare a boiling water bath and 5 regular mouth pint jars. (See canning basics .) Place lids in a small saucepan over very low heat to simmer while you prepare the pickles.
Wash and trim beans so that they fit in jars. If you have particularly long beans, cut them in half. Combine vinegar, water, and salt in a medium saucepan and bring to a boil. While the pickling liquid heats, pack the beans into the jars, leaving ½ inch for headspace. To each jar, add 1 clove of garlic, 1 teaspoon dill seeds, and 1 teaspoon red chile flakes.
Slowly pour the hot brine over the beans, leaving ½ inch for headspace. After all the jars are full, use a wooden chopstick to work the air bubbles out of the jars. Check the headspace again and add more brine if necessary.
Wipe the rims, apply lids, and rings and process in a hot water bath for 10 minutes. Let pickles sit for at least 1 week before eating.
