Why You Should Think Twice Before Using Purple Beans For A Pop Of Color

Whether they caught your eye at the farmers market or you stumbled upon them in a specialty grocery store, purple beans can be dazzling if you've never seen them before. Similar in appearance to more common types of beans, like green beans, but with a dramatic indigo hue, one wouldn't blame you for buying a bunch simply to add aesthetic appeal to your next dish. This would be a mistake, however, because we have some bad news for you: Purple beans don't retain that vivid violet color once they are cooked.

The reason purple beans lose their color relates to why the beans are purple in the first place. These beans contain very high amounts of pigments called anthocyanins. These pigments can appear red, purple, or even blue and are naturally found in fruits, vegetables, and grains such as blackberries, pomegranates, red onions, and even black rice. While these pigments are stunning, their color is not likely to last once the produce containing them hits the heat of a pan, pot, or oven. 

This is because, as the beans are heated, the water-soluble anthocyanins will slowly leach out as the cell walls within the plant tissues burst, and the bright color will eventually dissipate. While this may come as a surprise to the unprepared home cook, it doesn't mean that the beans will end up unappetizing. The remaining dark green color is still perfectly palatable, as is the taste of the bean.

When to use purple beans

Purple beans, even those that are no longer purple, still make a great addition to any meal. They have a pleasantly tender yet snappy texture not unlike that of traditional green beans. They also have a somewhat similar flavor with their earthy, verdant notes — though they are notably sweeter. As such, they can easily be incorporated into any recipe that calls for a comparable vegetable, either as a component in a main dish or as the star of a side. Blanching, adding them toward the end of cooking, and soaking them in lemon juice may also preserve some of their color. 

There are many ways to prepare purple beans. For a purist approach that highlights their natural sweet taste, opt for a simple technique such as boiling or steaming, then toss in a neutral oil with your seasoning of choice. For a richer flavor, try oven-roasting the beans on a hot pan so that they take on some golden color and caramelization. Once cooked, feel free to enjoy the beans on their own or use them as a substitute in another recipe, such as this classic green bean casserole or this refreshing green bean potato salad. They are also tasty raw in all their purple glory!