How to cook sweet potatoes

Learn how to buy, store and cook sweet potatoes - a highly nutritious and versatile vegetable.

By Moira Adams

There's nothing particularly difficult about cooking sweet potatoes, provided you remember one key fact: a sweet potato is not a potato. Although you can use similar cooking methods for both, the results are not the same. That said, sweet potatoes are easy to cook. I often serve them as part of a family dinner, and they give consistently good results.

Buying and storing sweet potatoes

Always choose sweet potatoes that are firm. If they yield when you press them, they're beyond their best. Make sure they are free from scratches, blemishes and sprouting.

Sweet potatoes should be stored in a dark, cool place, but never refrigerated. Keeping them below about 55°F (13°C) will cause the centers to harden, and to stay hard even after cooking. You can, of course, refrigerate the potatoes after they've been cooked. Many recipes can also be frozen.

Don't confuse sweet potatoes with yams - although in the USA yams are often incorrectly labeled as sweet potatoes. A yam is darker, more fibrous, and not at all sweet. This article refers only to sweet potatoes, that is, those with an orange skin and either orange or white flesh (see photo, above).

Boiling, steaming and mashing

You can boil or steam sweet potatoes in the same way as ordinary potatoes, except that the cooking time will be a little less. Wash them gently, cut them into small-to-medium pieces, and drop them into a pan of boiling salted water or place them in the steamer. As soon as they're tender, drain and serve.

Because of their strong flavor, you wouldn't normally serve sweet potatoes as the main carbohydrate source in a meal, as you would with normal potatoes. They are usually served in smaller quantities, as an extra vegetable. Or you can mix the two types - they go very well together.

That's especially true if the potatoes are mashed. I particularly like using a mixture of two parts normal to one part sweet as a mashed potato topping for dishes like my vegetarian shepherds pie (see picture, right).

Baking

For me, this is easily the best way of preparing sweet potatoes. Baked in foil, they make a delicious accompaniment to many different dishes.

Wash the potatoes carefully, but keep them whole. Prick the skins in several places with a fork, then brush them with a generous layer of olive oil or other light vegetable oil. Wrap them in aluminum foil, and bake at 400°F (200°C).

The cooking time will depend on the size and how many other items are in the oven. As a rough guide, allow 40 to 50 minutes if they're small, otherwise about an hour. They're done when you can easily slip a knife into the center.

When the potatoes are ready, remove the foil (it'll be hot, so handle it carefully) and serve straight away.

For a fancier way of serving baked sweet potatoes, proceed as above, but when the potatoes are ready, cut them in half, and scoop out most of the flesh, leaving a reasonably thick layer at the edges. Mash the part that you removed with a little butter or cream. You can also try adding a small amount of orange juice or sweet sherry if you like. Season with salt and pepper.

Divide the mash between the shells, and return to the oven for another ten minutes. I'm sure you'll enjoy the result.

Roasting

Roasting is perhaps the easiest way of preparing sweet potatoes, especially if you're roasting other vegetables at the same time. They go very well with eggplant (aubergine), zucchini (courgettes), mushrooms and peppers. In fact, a dish of those roasted vegetables, topped with a layer of haloumi or mozzarella, and served with rice, makes a wonderfully nutritious vegetarian meal - and one that's very easy to put together.

Another attractive option is to roast the sweet potatoes and other vegetables with some tofu cubes, as in this picture. In this case, I served the dish with cous cous, which makes a pleasant change from rice.

Unlike with baking, you should peel the sweet potatoes before roasting them. Cut them into wedges or slices about half an inch (1 cm) thick. Place them in an oiled roasting tin, either on their own or along with other vegetables. Sprinkle a little olive oil, salt and pepper over the top.

Place the tin in an oven which is pre-heated to 400°F (200°C). While the vegetables are cooking, turn them occasionally with a wooden spoon or spatula. They should take about 30 to 40 minutes to cook, depending on their size.

Spicing them up

I sometimes like to introduce a little variety to my sweet potatoes by sprinkling them with Indian spices immediately before putting them in to roast. You can use either a mixture of ground coriander, turmeric and cumin, or ready-made curry powder. Either way, allow about a teaspoon of spice for one large potato.

Candied sweet potatoes

Finally, here's a delightful recipe that will go down well at Thanksgiving or Christmas, or at any other time of the year. A dish of candied sweet potatoes is a delicious accompaniment to a nut loaf or lentil roast, and is quite easy to prepare.

Start by boiling the sweet potatoes whole (or cut them in half if they're particularly large). Cook them until they just start to soften. When they're ready, cut them into slices. Arrange these in a single layer in an oiled shallow oven dish or oven-proof plate. The slices should overlap slightly, but take care to leave as much as possible exposed.

Dot the potatoes with small pieces of butter, or brush with olive oil. Then cover them with a thin layer of maple syrup, using a fork to spread it evenly. If you don't have any maple syrup, you can use brown sugar instead.

Put the dish in an oven which is set to 360°F (180°C). Cook for about 20 minutes, then remove from the oven, and sprinkle over a couple of tablespoons of orange or lemon juice, and, optionally, a similar quantity of brandy or rum.

Return the dish to the oven for another ten minutes or so. It will be ready when the glaze is completely brown.

These are just a few of the many ways of preparing sweet potatoes. Whichever method you adopt, I'm sure you'll enjoy this versatile and nutritious vegetable as much as I and my family do.

December 2010

Please note: Neither Veg World nor its contributors are qualified to give medical or nutritional advice. If in doubt, always consult a suitably-qualified professional.