Sweet Potatoes vs. Yams: What’s the Difference, and Why It Matters in Your Kitchen

Gain confidence in selecting and cooking the right root for every recipe.

By Medha deb

Created on Sep 21, 2025

Gain confidence in selecting and cooking the right root for every recipe.

Sweet Potatoes vs. Yams: What’s the Difference?

Many home cooks encounter confusion at the grocery store: are sweet potatoes and yams the same thing? Although these root vegetables are often used interchangeably in recipes and markets, they are botanically distinct — and understanding the difference can improve both your cooking and your knowledge of food history. Let’s break down the key facts, settle the sweet potato vs. yam debate, and give you practical tips for your kitchen.

The Origins: Sweet Potatoes and Yams Are Not the Same

Sweet potatoes (Ipomoea batatas) are native to Central and South America and are part of the morning glory family. They have been a staple crop for centuries in the Americas.

Yams (Dioscorea species), meanwhile, originated in Africa and Asia and are part of the lily family. They are far less common in U.S. supermarkets and have a different appearance, texture, and taste compared to sweet potatoes.

Main Differences at a Glance

Characteristic	Sweet Potato	Yam
Botanical Family	Morning Glory (Convolvulaceae)	Lily (Dioscoreaceae)
Origin	Central/South America	Africa/Asia
Skin	Thin, smooth, can be tan, copper, or purple	Thick, rough, bark-like, often dark brown
Flesh	Varies: orange, white, or purple; moist	White, purple, or reddish; starchy, dry
Taste	Sweet, creamy	Bland, starchy, earthy

Why the Confusion Between Sweet Potatoes and Yams?

Most American supermarkets and recipes commonly mislabel sweet potatoes as “yams.” This confusion arose centuries ago, especially in the American South, when orange-fleshed sweet potatoes were introduced widely. To distinguish them from the paler, firmer-fleshed types, marketers called the orange variety “yams” — borrowing the name from the African tubers, though they are unrelated.

Today, what you’re likely eating—candied yams at Thanksgiving or mashed yams in recipes—are almost always sweet potatoes, not true yams.

Quick Tips to Tell Them Apart

If you see a vegetable in a standard U.S. supermarket labeled “yam,” it’s probably a sweet potato with orange flesh.
True yams are usually only found in specialty international markets and are much larger and rougher in appearance.
Orange flesh with a coppery skin? Sweet potato. Very large, starchy, and with bark-like skin? Likely a yam.

Types of Sweet Potatoes

There are two main types of sweet potatoes commonly available in U.S. stores:

Firm Sweet Potatoes: Tan or light yellow skin with paler, firm flesh that stays dry and firm when cooked.
Soft (Orange) Sweet Potatoes: Copper or reddish skin with bright orange flesh, becoming soft and creamy when cooked. This is the kind most people use for pies, casseroles, and baked dishes.

Some markets label firm types as “sweet potatoes” and soft types as “yams,” though both are sweet potatoes. True yams are rarely available in regular grocery stores.

What Are True Yams?

Yams are a favorite vegetable in West African, Caribbean, and Asian cuisines. They are:

Much larger than sweet potatoes, sometimes up to five feet long.
Covered in tough, bark-like skin.
Starchy and less sweet, often needing to be soaked or boiled before cooking.
Bland or slightly nutty in taste and very dense in texture.

If your recipe specifically requires a true yam—such as for traditional African fufu or pounded yam—you’ll need to source them from an international grocer.

Sweet Potato Nutrition and Health Benefits

Sweet potatoes are highly nutritious:

Rich in beta-carotene (especially the orange varieties, which your body converts to vitamin A)
Good source of fiber, potassium, vitamin C, and manganese
Antioxidants and anti-inflammatory compounds support overall health
Lower in calories than many starches and have a low-to-moderate glycemic index

Yams are also beneficial, being higher in starch and important for certain cultural diets, but they have less beta-carotene and vitamin A than sweet potatoes.

How to Cook with Sweet Potatoes

Sweet potatoes are extraordinarily versatile in the kitchen. Here are some classic and modern ways to prepare them:

Baked: Roast whole at 400°F until fork-tender, then split and serve with butter, herbs, or brown sugar.
Mashed: Boil, steam, or roast, then mash with milk and butter, or for a healthier version, with a splash of broth and olive oil.
Casserole: A traditional favorite, often topped with marshmallows, pecans, or a brown sugar crumble (see classic Southern recipes below).
Fries (Baked or Fried): Slice into sticks, toss with olive oil, and bake or fry for a nutritious alternative to potato fries.
In Soups & Stews: Add diced sweet potato for extra body, sweetness, and nutrients.
Roasted Cubes: Season and roast for salads or grain bowls.

Classic Sweet Potato Casserole Recipe Overview

The sweet potato casserole, especially popular during Thanksgiving, combines creamy, mashed sweet potatoes with sugar, eggs, and vanilla for a custardy base. It’s often topped with a pecan streusel or a blanket of toasty marshmallows.

Key Ingredients:
- Sweet potatoes
- Butter and/or cream
- Brown sugar and/or maple syrup
- Eggs (for richness and structure)
- Vanilla extract, sometimes cinnamon or nutmeg
- Topping: Marshmallows, pecans, crumb mixture, or all three
Making It:
- Roast or boil sweet potatoes until tender; mash with other ingredients
- Spread into a buttered baking dish, top as desired
- Bake until bubbly and golden on top

Spotlight on: Soul Sweet Taters (Southern-Style Sweet Potato Casserole)

This famous family recipe pairs a luscious, sweetened sweet potato mixture with a crunchy pecan-brown sugar topping. It’s a side dish with dessert vibes, and a beloved holiday staple.

Essential Steps

Bake sweet potatoes until tender and scoop out the flesh.
Mash with sugar, milk, eggs, vanilla, and salt. A few lumps are okay!
Top with a mixture of brown sugar, chopped pecans, flour, and butter.
Bake until the topping is crisp and golden.

How to Select, Store, and Prepare Sweet Potatoes

Choose firm, unblemished sweet potatoes. Avoid wrinkled skin or spots.
Store in a cool, dark, well-ventilated space — not the refrigerator, which can alter texture.
Scrub just before cooking. Peel if desired, though the skin is edible and full of nutrients.
If slicing ahead, keep submerged in water to prevent browning, and cook within 24 hours.

True Yam Shopping and Preparation Tips

Look in international groceries, especially African or Caribbean markets.
Select dense, heavy tubers without soft spots or mold.
Peel thoroughly (the skin is not edible), then boil or steam until tender. Yams may require longer cooking and soaking to soften.

Table: Nutritional Comparison (Per 100g, Cooked)

	Sweet Potato (Orange)	Yam
Calories	~86	~118
Carbohydrate	20g	28g
Fiber	3g	4g
Sugar	4.2g	0.5g
Vitamin A	19,218 IU (over 400% DV)	9 IU
Vitamin C	2.4mg	12mg
Potassium	337mg	816mg

Popular Recipes Featuring Sweet Potatoes

Baked Sweet Potatoes: Simply roasted and served with your favorite toppings.
Sweet Potato Casserole: A holiday favorite, topped with marshmallows or pecans.
Sweet Potato Pie: A Southern classic dessert.
Stuffed Sweet Potatoes: Split open and filled with vegetables, beans, or pulled pork.
Roasted Sweet Potato Wedges: Perfect for snacks or sides.
Sweet Potato Hash: Diced and sautéed with spices and vegetables, often for breakfast.

Getting the Most Out of Sweet Potatoes in Your Kitchen

Whether you’re using sweet potatoes or exploring yams from a specialty grocer, a few techniques can elevate your dishes:

Roast whole for peak sweetness; caramelization develops natural sugars.
Combine with savory elements (chili, cumin, or cheese) to balance sweet potato’s richness.
For casseroles, keep the texture slightly chunky for a rustic feel, or whip for a light, fluffy finish.
Use leftovers in pancakes, muffins, or toss into salads.

Old Myths and Modern Understanding

It’s a common misconception that sweet potatoes and yams are the same — but now you know how to spot, cook, and savor both. In most American kitchens, that coveted “yam” side dish is truly sweet potato, and you can proceed with your favorite recipes confidently.

Frequently Asked Questions (FAQs)

Q: Why do American supermarkets label sweet potatoes as yams?

A: The labeling stems from marketing in the early 20th century, meant to distinguish orange-fleshed (soft) sweet potatoes from the paler-fleshed (firm) type. True yams are rare in supermarkets and are not botanically related to sweet potatoes.

Q: Can I substitute yams for sweet potatoes in recipes?

A: In most U.S. recipes, “yams” means sweet potatoes. True yams have a different texture and flavor—much starchier and less sweet—so the swap could drastically change your dish. For most baking, casseroles, or pies, always use sweet potatoes unless the recipe specifically calls for imported yams.

Q: Which is healthier: sweet potatoes or yams?

A: Both are nutritious, but sweet potatoes are significantly higher in vitamin A (beta-carotene) and supply more natural sweetness, while yams are starchier and higher in potassium. If you want a beta-carotene boost, pick orange sweet potatoes.

Q: How do I store sweet potatoes to keep them fresh?

A: Store them in a cool, dry, well-ventilated place—never the fridge. Storing in the fridge changes the texture and possibly the flavor. If cut, keep submerged in water in the fridge for up to 24 hours and cook soon.

Q: Are sweet potato skins edible?

A: Yes. The skin of sweet potatoes is thin, nutrient-rich, and completely edible. Just scrub well before cooking.

Final Kitchen Tips and Inspiration

Cook sweet potatoes whole for peak sweetness, or cube for speedier roasting.
Pair with savory flavors to balance their sweetness.
Try varieties: orange, Japanese (purple skin, white flesh), or purple for antioxidants and color.
Rely on reliable labeling at local, Asian, or African markets for true yam purchases.

Armed with this knowledge, you can shop, cook, and savor sweet potatoes and yams with confidence—bringing more flavor, color, and tradition to your table.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

Read full bio of medha deb