”Butter beans” are the common name for Phaseolus lunatus, a legume considered by many to be a vegetable. They are often compared to the more common lima bean, and the two share many similarities — but most horticulturists argue that they are not, in fact the same, despite their similar biological traits. They are very common in the cooking traditions of the American South, and also feature in many Mediterranean dishes.
Butter beans are typically white or cream colored, and are flat and slightly curved in shape. They typically measure between 0.25 and 1 inch (approximately 0.6 to 2.5 cm) in length. Some varieties are speckled with brown or deep purple spots, though most of the time these color aberrations are limited to home-grown varieties — the vast majority of commercially-available beans are uniformly cream colored.
There are two theories for how the beans earned their colloquial name. The first relates to their color; most are the shade of fresh cream butter. Taste may also be the origin, as the beans have a smooth, almost buttery taste after cooking.
Relationship to Lima Beans
Butter beans are genetically very similar to lima beans, and there is some dispute when it comes to whether or not they are actually a variety of lima bean. Most limas are slightly larger with a green tint, though they are known to come smaller; sometimes, they are even white.
Horticulturists typically agree that lima beans were originally cultivated in the mountainous regions of South America, while butter beans come from the warmer climes of Mexico. They are genetically similar, and can often be used interchangeably in recipes. Most legume aficionados dispute the claim that they are one and the same, however.
Culinary Uses and Popularity
Butter beans are very commonly used in the cuisine of the American South. They are often boiled and served alone as a side dish, usually seasoned with little more than salt and pepper and a bit of butter. They also feature heavily in casseroles and bean pie dishes. Some cooks will also add them to corn bread, soups, stews, and chilis.
Availability and Growing Season
Fresh butter beans typically reach their harvest peak in the late summer months. Gardeners usually plant them just after the last frost of the year, as they are quite sensitive to cold soil. The plants must usually be staked, as most will climb; they will usually produce seed pods by early spring, and will develop into fully grown beans by mid to late summer. The seed pods are often reserved for the next season’s growing, though seeds are available from many nurseries and commercial garden supply centers, as well.
The beans’ popularity has led many commercial food production companies to package them and sell them year round. Canned varieties are the most popular, though sometimes dried or frozen versions can also be purchased. Most cooks prefer to work with fresh beans, but wide commercial availability has made it easy to make butter bean recipes year-round.
Butter beans are generally considered quite healthful. They are high in vitamin C, vitamin A, and thiamin; they are also a good source of protein and are very low in calories and fat. Of course, these positive nutritive benefits can be overshadowed by the method of preparation — slathering the beans in butter or thick sauces can make for some highly caloric dishes.