Beans—both string and shell—give substance and texture to summer dishes. Blanched string beans tossed with sliced onions and tomatoes or with pasta and pesto make colorful, tasty starters. Fresh shell beans make a light, satisfying main dish, tossed with cherry tomatoes, shallots, chopped basil, and a lemon vinaigrette, or with parsley, garlic, and olive oil, served over hot fettuccine. And both string and shell beans are essential for a true Provençal soupe au pistou, simmered along with other summer vegetables and served with a spoonful of pesto in each bowl.
Different varieties from the same species
Both string beans and shell beans come from the same plant species (Phaseolus vulgaris) but from different varieties within that species. String beans are whole, immature pods, while shell beans are the seeds inside more mature pods. Any string bean variety will produce seeds that can be shelled, but the pods of most shell bean varieties are too tough to be eaten.
You’ll find good string beans from early summer until frost. The peak season for shell beans is midsummer into fall; however, fava beans grown during late spring and early summer have the best flavor.
String beans—with or without strings
String beans are also known as snap beans or green beans, even though they can also be yellow or purple.
String beans are best when they feel heavy and plump. They should break with a good, clean snap when bent. Store them in a plastic bag in the refrigerator for no more than a couple of days.
To prepare string beans, first check for the string. Most modern varieties don’t have much of a string, as it has been bred out. To check, snap off the stem end. If you find just a small string attached, don’t bother pulling it; just go ahead and work in bunches, cutting off the tops and tails. If the string is long and tough, work individually, snapping off both ends of each bean and pulling the string down from top to tail. Some cooks like the look of the tails left on, but I find that they’re tough and unpleasant, and I prefer to cut or snap off both ends.
To cook string beans, boil them in a large pot of salty water until crisp-tender. I learned that it was best to stop the cooking by plunging the beans into an ice-water bath, but now I prefer to undercook them slightly, drain them, lay them out on a towel, and refrigerate them. This method preserves lots more flavor. If you’re serving beans hot as a side dish, cook them just before serving or reheat them in butter or garlic and olive oil just before serving.
Fresh shell beans are worth seeking out
If you’ve only ever eaten dried beans, fresh shell beans will be a revelation. There are thousands of varieties, in many beautiful colors and patterns, that taste creamy and flavorful when cooked. Look for them in farmers’ markets and specialty stores.
Shell beans are at their best when the pods are full and slightly soft, indicating the beans inside are mature but not dry. Avoid pods that are withered or have watery or brown spots. Keep shell beans at room temperature for a few days, or up to a week in the refrigerator in a paper bag to allow for a little air circulation.
To prepare shell beans, break open the pods along the natural seams and use your thumb to coax out the beans.
To cook shell beans, simmer them until tender in unsalted water or low-salt stock (at this stage, salt can toughen beans) with half an onion and a small bundle of bay leaves, fresh thyme, and parsley stems. The exception is fava beans, which have a tough outer skin that needs to be removed. Before simmering, blanch shelled favas in boiling water for a minute or two, drain, and put them into an ice bath so the tough skins will slip off easily.
Once shell beans are simmered until tender, they’re ready to be marinated for a salad, tossed with pasta, or puréed with olive oil for a delicious spread.