Mashed Sweet Potatoes

Has anyone ever asked you to pass the candied yams at a holiday dinner? A 1930’s marketing campaign confusingly called sweet potatoes yams and the name stuck. A true yam is a tropical vegetable commonly grown in Africa, South America and the Pacific Islands, and is rarely seen in U.S. markets. Yams grow up to seven feet long and have a rougher outside, and a starchier inside than sweet potatoes.

The standard sweet potato, bright orange and elongated with ends that taper to a point, is grown and consumed abundantly in the southeast United States. This one, as well as the dark-orange varieties, is rich in beta-carotene (precursor of vitamin A), whereas red and purple sweet potatoes are excellent sources of anthocyanins. Most sweet potatoes get sweeter when cooked due to the action of maltase, an enzyme that breaks down the starch. Slower cooking methods, such as baking and roasting, give the maltase more time to work yielding a sweeter product.

Selection and handling of sweet potatoes:

• Choose firm roots with no cracks or bruises.

• Handle with care. Even a small bruise spreads quickly below the surface and spoils the entire vegetable. 

• Do not refrigerate; storing fresh sweet potatoes at temperatures below 55ºF may result in “hard core” causing the center to remain woody when cooked. Store in a cool cupboard or on the countertop. 

• Despite the potato name, sweet potatoes are not good keepers. Plan to use sweet potatoes within a week to 10 days following purchase. 

• Scrub well before cooking. If yours are organically grown sweet potatoes, you can eat the entire vegetable, including the skin. 

• Peel your sweet potatoes if they have been treated with wax or dye. Once peeled, cover with water to prevent oxidation until you’re ready to cook them. 

Harvest time in Michigan is September and October. It takes six to eight weeks after harvest for sweet potatoes to reach their peak in sweetness. When stored in temperature- and humidity-controlled warehouses, the sweet potato’s shelf life is extended to 12 months making them available in the grocery store year-round. Sweet!