Which sweet potatoes should you buy?

baked sweet potatoes
© Oven-roasted sweet potatoes; 400F for 40 minutes. (Photo: Melissa Breyer)

Confused by all the yam and sweet potato options? Learn what to expect in terms of flavor, textures, and best uses here.

Once upon a time we simply had sweet potatoes in the United States; now we have all kinds of different types, sometimes some are called yams, other times they are called sweet potatoes, sometimes they are called both. Some have orange flesh, some are creamy white, and some come in shades of vibrant purple. What does it all mean???

The difference between yams and sweet potatoes

First things first, some clarification. You may think that those are candied yams on the holiday table, but they are most likely not. What we buy here in the States are all, botanically speaking, sweet potatoes – unless you are shopping in an international market. True yams are native to Africa and Asia, and are white-fleshed, dark-skinned, dry and starchy.

Prior to the middle of the 20th century, the U.S. only had firm, white-fleshed sweet potatoes on the market. When their soft, orange-fleshed brethren became available, the new guys were referred to as yams to differentiate between the two – and we've been confused ever since. Now the USDA requires that products labeled as "yam" also include the term "sweet potato" – technically, they are all sweet potatoes. If you see "yams" in a recipe, it is referring to orange-fleshed sweet potatoes

How to cook sweet potatoes

Of course there are endless ways to prepare these beauties, but here are the two basic methods I used for the purpose of this story. Basic, but delicious.

BAKED WHOLE
Sweet potatoes do not like to be baked like a regular baked potato does; they prefer a longer bake at a lower temperature, which allows more of the starch to convert to sugars, which caramelize for a deeper flavor. Cook's Illustrated points to the prefection of chef Michael Solomonov's baked sweet potato – one which results in interiors that are "not just tender but downright plush, and their flavor ... concentrated to the point of tasting caramelized, with hints of molasses." Solomonov's glorious method calls for baking them at a 275F-degree oven for two and a half hours. For a shortcut, CI pre-cooks them in the microwave; since I don't have a microwave, I go for the whole two and a half hours in the oven. Obviously, this is not a summertime endeavor.

ROASTED in HALVES
A quicker way to oven cook sweet potatoes is in halves, which is the perfect middle road between roasted chunks and baked whole. I love this method for most varieties. They become a bit denser than when baked, the cut side caramelizes just a bit, and the flavor is deep and wonderful. And again, it is much quicker.

How-to: Cut potatoes in half, lightly oil cut sides, place face down on a light colored baking sheet (they may brown too much on a darker sheet), bake at 400F degrees until soft. The ones pictured on top ranged in size from 12 to 16 ounces (whole) and took 40 minutes.

Which types to buy

I shopped all around my NYC neighborhood to see which varieties were commonly offered, and came up with these five, which are the ones I see in other places as well. The farmer's market has all kinds of gorgeous heirloom varieties – and those may be the very best for many reasons (local, sustainable, support biodiversity, etc) – but since those are so specific to specific farms and locations, I stuck with these supermarket types, which should be widely available. I was able to find organic versions of them all.

Jewel

jewel sweet potato© Melissa Breyer
While Beauregards may be the most common sweet potato, Jewels are right next to them in terms of being a great, classic sweet potato. They have a pretty, thin orange skin, and bright orange flesh that screams "sweet potato." (Or "yam," wrong as that may be. Shrug.) They are very sweet and taste like deeply-flavored carrots. Their higher water content makes them very fluffy in texture and their flesh melts in the mouth, but they can get soggy.

Great for: Boiling, baking, casseroles, sweet potato pie, adding to hummus.

Garnet

garnet sweet potato© Melissa Breyer
You can spot a garnet by its reddish-purple skin which reveals a striking orange interior. These are super velvety, with a denser texture and more complex flavor than jewels. Garnets kind of bring to mind plums and some vanilla – it's a sweet, gorgeous, deep flavor. Texture is moist like jewels, and cal also get soggy.

Great for: Roasting, baking, stuffing, mashing, casseroles, soup, pureeing, pies.

Hannah

Hannah sweet potato© Melissa Breyer
The original sweet potato! Before the orange friends came into the picture, types like Hannah, with tan skin and light interior, were the norm. I love these potatoes – though they are pretty different from the orange ones. They are almost like a Yukon Gold potato infused with honey. They are firm, dense, and creamy, yet drier so they flake more like a regular potato. Because of that reduced moisture, they don't make a great substitute for orange-fleshed ones, but they are fabulous in the right application.

Great for: Perfect, actually, for roasting in chunks since they hold their shape, roasting in halves, baking, mashing, putting in stews and soup, fries.

Purple

purple sweet potato© Melissa Breyer
Purple sweet potatoes are shockingly pretty – an ashy purple skin opens to reveal a vivid purple flesh – to my eye they are the prettiest by far. (The one here is a Stokes variety.) That said, they are dense, dry, and not super sweet – not in a bad way, just don't expect an explosion of velvety sweetness with that gorgeous color. They are not the best roasted since they dry out easily. Cooked properly, however – either baked whole or with moisture – they are still tender, and have lots of perfume and vanilla flavor.

Great for: A slow bake, mashed, simmered in curries, soups, added to other dishes for their exquisite color.

Japanese

japanese sweet potato© Melissa Breyer
To cut into a Japanese sweet potato is a little anticlimactic. Their purple skin may hint at excitement inside, but they don't even have that great orange hue, they are just a pale yellow. But don't be fooled, they are the best of all! They are drier than orange varieties, and it totally works to their advantage – the flesh holds it shape, and is dense and strachy, but also inexplicably creamy at the same time. And they have the best flavor – it is deep, beautifully balanced, and makes me think of honey and chestnuts. I am eating a leftover one right now, straight from the fridge, and I swear it tastes like roses. These are my desert island sweet potatoes, without a doubt.

Great for: Roasting in halves or chunks, stuffing, steaming, fries, mashing with coconut milk, soups, stews, eating leftovers straight from the fridge.

All of these sweet potatoes have their merits; and while they may not all be equally exchangeable in recipes, it can be great fun to play around with them. When in doubt, you can always mix and match, too, since the various moisture levels can work to compliment each other – like make chunky mashed sweet potatoes using jewel and purple varieties, so delicious and pretty.

And on that note, BRB, I have more sweet potatoes to eat.

Which sweet potatoes should you buy?
Confused by all the yam and sweet potato options? Learn what to expect in terms of flavor, textures, and best uses here.

Related Content on Treehugger.com