Everything You Need to Know About Sweet Potatoes
Regardless of the season, sweet potatoes are a versatile way to bring a healthy, colourful dish to the table. This vibrant veggie is loaded with fibre and nutrients, including vitamins A and C, beta-carotene and a slew of antioxidants.
Photo from North Carolina Sweet Potatoes
In North America, most “yams” sold in mainstream grocery stores are actually sweet potatoes. There are many varieties of sweet potatoes and they can have yellow, red, purple or brown skin and yellow, orange, orange-red or even purple flesh.
The common orange-fleshed variety was introduced to the United States several decades ago. In order to distinguish it from a white potato everyone was accustomed to, producers and shippers chose to label them “yams”. Today the U.S. Department of Agriculture requires labels with the term “yam” to be accompanied by the term “sweet potato.” So, unless you specifically search for yams, which are usually found in specialty stores or stores that include a variety of produce from different parts of the world, you are probably buying sweet potatoes.
Although both vegetables are tubers and the terms sweet potato and yam are often used interchangeably, the two vegetables are not technically related. Yams, which are native to Africa and Asia, are related to lillies and grasses (family Dioscoreaceae). Sweet potatoes are in the morning glory family (family Convolvulaceae).
When you know what to look for it is easy to tell them apart, for the real difference lies in their texture and colour. Sweet potatoes are typically more uniform in shape, have tapered ends and a smooth external appearance, compared to a yams which are rough with scaly and/or fibrous brown or black skins. Sweet potatoes are also roughly the same size as potatoes, while yam tubers can grow up to 1.5 meters (4.9 feet) in length and weigh up to 70 kilograms (154 lb). Usually yams are cut down to pieces that are 6-12 inches long when you see them in stores. Inside, yams have off-white, purple or red flesh, decidedly different than that of a sweet potato.
In terms of flavour, yams and orange-fleshed sweet potatoes tend to be sweeter and moister than white-fleshed sweet potatoes, which are dry and crumbly in texture, like a white baked potato.
How to Select and Store Sweet Potatoes
Look for small to medium sized sweet potatoes without soft spots, cuts, cracks, or bruises. Try to avoid any tubers that have white stringy filaments, as it is a sign that they are over-mature and possibly tough in texture.
Despite their hardy appearance, sweet potatoes are in fact more fragile than potatoes and should be handled with care. Also, make sure you add sweet potatoes to the list of foods that you shouldn’t store in the refrigerator. Instead, it is recommended that you keep them in a cool, dark, well-ventilated place, where they will keep for 2 to 4 weeks. Once cooked, sweet potatoes should be kept in the fridge for 3-5 days.
Speaking of which, once a sweet potato has been cooked (whether whole, in large slices, or cooked and mashed), it can be stored in an airtight container and frozen for up to a year. To keep sweet potatoes from darkening in the freezer, and to preserve their vibrant colour, coat in a lemon juice/water solution (about 1 part lemon juice to 2 parts water).
How to Prepare Sweet Potatoes
Scrub sweet potatoes well under cold, running water. You can cook them with the skin on or off. If you choose to cook them with the skin on, you’ll find that the peel will come away easily after cooking – if you wish to remove it.
If roasting whole, it’s best to leave the skin on. Just make sure you pierce them a few times like you would with a baked potato. You can cut sweet potatoes into cubes for soups, stews, and chili or for roasting or boiling. They can also be cut into wedges or fries for frying. Alternatively, try cutting them into thick rounds to grill as a veggie “steak”, or cut length-wise to create bigger, flat pieces that are great in a sandwich.
You can also grate sweet potato to add to soups, make hash browns and sweet potato pancakes, or to make a savoury sweet stuffing for turnovers.
The sweet potato can be prepared and cooked just like the potato, and the required cooking time for each is identical. Common cooking methods for sweet potatoes include baking, grilling, boiling, mashing, deep-frying, sautéing, steaming, and microwaving.
How to Microwave: To cook a whole unpeeled sweet potato in the microwave, prick it several times with a fork, wrap it in a paper towel, and cook on high for 5 to 7 minutes; halfway through cooking, turn the potato over. Let it cool for 2 minutes before serving.
How to Bake: When baking whole in the oven, leave unpeeled, prick it in several spots to prevent it from splitting, and bake for 45 to 60 minutes, until tender.
How to Boil: Most people prefer to peel their sweet potatoes before boiling. If cut into smaller cubes (approx. 1 inch square), they will boil in approx. 15-20 minutes. However if you cut them into large chunks or quarters, you might decide not to peel them before putting them into the water because after boiling for 20 to 30 minutes, the peel will come away easily.
How to Grill: First wrap each sweet potato in aluminum foil and place in BBQ to cook with indirect heat for about an hour, until they are soft. Timing will depend on size/thickness of the sweet potato. Remove from grill and unwrap. Submerge in ice bath to halt the cooking process. Let cool for about 30 minutes. Then, cut into thick steaks—about ½ – ¾ inch thick. Coat sweet potatoes well in olive oil before placing on a grill. Grill for 3-4 minutes on each side until you get beautiful char marks. Serve immediately.
Sweet Potato Tips
Cook sweet potatoes in their skins to maintain more of their nutritional value.
- Try adding equal parts sweet potato and yellow or white potato when making mashed potatoes (you can boil them together). The sweet potato will add a hint of sweetness and colour that isn’t overpowering. It’s a great way to include a variety of vegetables into your family’s diet.
- Store your sweet potatoes in a cool, dark place, but do not refrigerate them while raw.
- Try this time saving tip! Bake more sweet potatoes than you need. Then let the extras cool. When cool enough to handle, you can cut off one of the tapered ends and simply squeeze out the cooked flesh to add into recipes or prepare into mash for another day.
Herbs & Spices: chili pepper, cilantro, cinnamon, coconut, garlic, ginger, nutmeg, rosemary, thyme, allspice, cinnamon, and clove
Produce: lime, onions, carrot, salt, thyme, walnuts, oranges, pineapple, apples, and potato
Savoury: pecans, maple sugar, and rich meats such as pork, duck, ham, and poultry
Other: butter, cream, rum, brown sugar, maple sugar/syrup, honey
For an inspiring flavour combination try one of the following sweet potato pairings:
- Sweet Potato + Chorizo sausage
- Sweet Potato + Bacon + Rosemary + Onions
- Sweet Potato + Thai Curry Paste + Coconut Milk
- Sweet Potato + Feta + Paprika
- Sweet Potato + Pecans + Maple Syrup
- Sweet Potato + Olive Oil + Salt + Pepper
- Sweet Potato + Prosciutto + Kale
Sweet Potato Serving Ideas
Sweet potatoes make great fries and wedges, too. Try baking them or frying them just like you would with regular potatoes.
Instead of making potato skins, try baked sweet potato skins and top with bacon, sausage or chicken for a flavourful weekday meal.
Sweet potato also makes delicious and tender gnocchi. Try this Produce Made Simple recipe to impress your family and friends.
Play on the natural sweetness with pineapple to make this super simple but tasty side dish: roasted sweet potatoes and pineapples!
Sweet Potato Nutrition
According to the Canadian Nutrient File, 100 g of baked sweet potato has 2 g of protein, over 300% of Vitamin A, 32% of Vitamin C, 14% of potassium, 13% of fibre 3.3 g, 11% magnesium and 5% of iron.