Baked Purple Sweet Potato Mash (oven baked or boiled)

If you want to eat a rainbow, these sweet potatoes have just the color purple you’re looking for. Using an easy baking method and coconut milk instead of regular dairy, you'll get a creamy, substantial, and striking side dish to brighten up any plate.

Baked purple potato mash in a white bowl with a garnish of pineapple wedges and mint.

Since purple sweet potatoes are available year round, you can have this side dish with anything you would eat with regular potatoes or sweet potatoes.

Try them with Hawaiian salmon and sesame broccoli for a Hawaiian inspired meal. Or try a rainbow themed Thanksgiving meal with baked duck legs and dairy free green bean casserole.

Jump to:

Why You'll Like this Recipe
What are Purple Sweet Potatoes?
Ingredients
Instructions for Baked Purple Potato Mash
Substitutions
Variations
Variation: Boiled Purple Potato Mash
Equipment
Storage
Menu Ideas
Top tips
FAQ
Related plant based dishes:
Pairing
Food safety
Fortune Cookie 🥠

Why You'll Like this Recipe

It bakes in the oven while you cook the rest of the meal.
You won't miss the milk or heavy cream typical of a regular mashed potato or sweet potato.
The royal purple color instead of yams really does surprise your regular weeknight meal.

What are Purple Sweet Potatoes?

They are root vegetables, similar to orange sweet potatoes, that come in two main varieties:

Okinawan – Light brown/white skinned and can fit in the palm of a large hand. Grown in Hawaii and exported. Okinawa is an island in Japan and a designated blue zone where people live historically longer lives than other populations in part due to these purple potatoes.
Stokes – Purple skinned and the shape of longish, regular orange sweet potatoes

Raw purple yam sliced in half — The Stokes variety is a registered trademarked named, non-GMO purple sweet potato grown in California and found in grocery stores like Whole Foods Market.

Not to be confused with Ube

Ube is a Filipino yam that grows on a vine above ground and has a dark brown, rough skin.

Purple sweet potatoes may be called ube, but they are technically different.

What do they taste like?

If you close your eyes, it probably tastes like an orange sweet potato. However, I find them to be a little bit stringier and starchier.

Where can you buy purple sweet potatoes?

An Asian market, specifically one that stocks Chinese, Japanese, or Filipino products, will have all variations of purple colored potatoes including ube, Okinanwan, and Stokes.

The Stokes varietal is appearing at more and more big box stores including Whole Foods Market.

Alternately, it looks like Amazon conveniently sells them too.

How sweet are they?

Oh, that all depends. I’ve found the tiny, white skinned Okinawan varietal to be much, much sweeter than the large dark skinned Stokes varietal.

You can add more or less sweetness to taste with your choice of sweetener.

How long do you bake it for?

Some publications such as Southern Living and Parade say that you need to bake it for 90-120 minutes at 350 degrees F for premium moistness.

I cooked mine at 350 degrees F for 45 minutes until tender and still found them moist. They are a little starchier than orange yams anyway, so I didn’t expect them to be terribly moist.

Ingredients

Purple sweet potatoes - Use the version you can find such as Stokes or Okinawan. They cook and taste similar to regular orange or yellow sweet potatoes but are richer in anthocyanins - a nutrient with antioxidant properties. They generally have a long elongated shape similar to a yam. Purple sweet potaotoes should not be confused with the regular Peruvian purple potato that is not sweet at all.
Coconut milk - Regular coconut milk or light coconut milk will work. The potatoes are starchy, so you need some kind of fatty liquid to help smooth out the flesh.
Salt (optional) - Not necessary, but a little bit of salt helps bring out the flavor of the potatoes.
Sweetener (optional) - Use maple syrup, agave, honey, or other sweetener of your choice if needed. Not all purple sweet potatoes are actually sweet (even though they're called sweet).

See recipe card for quantities.

Instructions for Baked Purple Potato Mash

4 purple stokes potatoes on a baking sheet with a silicon liner.

Prick with a fork. Once it heats up, that steam needs to escape. Prick a few holes on all sides of the potatoes with a fork.

4 baked purple sweet potatoes on a baking sheet with a spoon scooping out the flesh.

Scoop flesh. Remove potatoes from the oven, cut in half, and scoop out all that purple goodness. If too hot, let sit a bit until cool enough to handle.

Ube mash in a brown bowl with a pat of butter

Mix in the goodies. I mixed in butter for creaminess and honey for additional sweetness. You could substitute with vegan butter or coconut milk and the sweetener of your choice (agave, maple syrup, coconut sugar, etc.) Also, a pinch of salt brings out the flavor of all that purple

Mashed purple yam in a brown bowl with a spoon

Serve. Ideally, this is served hot as a Barney inspired bed of sorts for your protein of the day. Alternately, I’ve seen this cooled, refrigerated and sprinkled onto salad as a healthy, colorful topping.

Hint: In the oven, purple potatoes are very forgiving. Any extra 5, 10 or even 15 minutes of baking won't hurt in case you forget to check on them. Boiling them in water, on the other hand, leaves your potatoes susceptible to getting water logged with even just a few minutes of overcooking.

Substitutions

Sweet Potatoes - This of course work with regular orange or yellow sweet potatoes.
Russet Potatoes - This recipe also works with regular russet potatoes. In fact, some chefs prefer roasting russets with rock salt instead of boiling them because you get a dried, fluffier interior.
Milk of your choice - Don't have coconut milk? Use another plant based milk or the milk of your choice.

Variations

Peel and Boil - Instead of roasting the potatoes, you could also boil chunks of peeled purple potatoes in water until tender. Drain, mash, and season.
Split in half (Baked Potato style) - Don't want to scoop the flesh out of the potatoes? Just split them in half and serve with a dollop of butter or make a little well for some coconut milk for each diner to deal with themselves. This is a preferable method if you can only find purple sweet potatoes that are really small.
Serve cold as a salad topping - If you don't add any coconut milk, you can dollop cold chunks of the mashed potato on top of salads. (I've seen it served that way in San Francisco!)

Variation: Boiled Purple Potato Mash

Purple potato cut into chunks on a wooden cutting board.

Peel and cut the potatoes into even sized two inch chunks.

Raw purple potato chunks in a silver saucepan covered with water.

Put the potatoes into a pot and cover with with about an inch of water. Bring to a boil over medium high heat.

Purple potatoes cooking in boiling water in a silver saucepan.

Once the water has come to a boil, lower the heat to medium and simmer at a low boil until the potatoes are cooked. This should take 7-10 minutes depending on how large the chunks are.

Drained and cooked purple potato chunks in a saucepan.

Drain the potatoes once the are easily pierced with a fork and cooked through.

Cooked purple potato chunks in a sauce pan with two dabs of butter.

Add your choice of seasoning ingredients: butter/coconut milk, coconut sugar, salt.

Chunks of purple potatoes being mashed with a fork in a silver saucepan.

Mash with a fork or potato masher.

Hint: It's an old chef's trick to return boiled potatoes to the warm saucepan they were boiling in. That helps dry them out, so you get less water in the final mash.

Equipment

No special equipment is required except for a baking sheet or other oven safe vessel. Parchment paper or silicon liners also help make for easy clean up.

To mash the potatoes, you will need a potato masher or fork works too.

Storage

Store up to 3 days in the fridge. You can also freeze this for up to a month.

Menu Ideas

Purple yam mash on a plate with turkey dinner — **Thanksgiving alternative**: Serve instead of orange yams on a thanksgiving inspired plate with a pomegranate seed garnish, delicata squash, sauteed greens, and baked duck legs.

A filet of Hawaiian salmon on a plate with broccoli and purple mashed potatoes behind it. — **Hawaiian theme**: Serve with a coconut milk "gravy," air fryer Hawaiian salmon with gochujang glaze, Korean broccoli salad, and pineapple wedges.

Top tips

1 ½ lbs of purple potatoes makes roughly 3 cups of purple potato mash. Each serving is about ¾ cup. This recipe serves 4 as a small side dish or 2 if you want a larger potions.
Can't be bothered to mash? Just split the potatoes in half after cooking and let everyone scoop and mix in their own toppings.
Don't like skin? Peel, chop, and and boil the potatoes in water until cooked through (about 7-10 minutes for 2" sized chunks.) Proceed with mixing in the coconut milk/butter/sugar as desired. Note this method adds more water to your potato, resulting in a looser consistency.

FAQ

What temperature do you bake purple sweet potatoes?

350 degrees F is hot enough to cook the potatoes evenly and thoroughly with less change of overcooking or burning.

How long do you bake purple sweet potatoes?

Depending on the size your potatoes, this will take anywhere from 40-60 minutes. They should be easily pierceable with a fork or knife with little to no resistance.

What is the nutrition of a baked purple sweet potato?

According to the USDA's Food Data Central site citing a nutrition label from Wegman's, 100g of purple sweet potatoes contains 85 calories, 1.54g of protein, 20g of carbohydrates, 3.1g of fiber, 30mg of calcium, 0.62mg of iron, 337mg of potassium, and 54mg of sodium. (The nutrition label was sourced from Wegman's organic purple sweet potato product. Wegman's is a chain of grocery stores on the east coast of the US.)

Looking for other recipes like this? Try these:

Pairing

These are my favorite dishes to serve with :

Purple potato mash in a white bowl with a garnish of pineapple wedges and mint.

Print Recipe

5 from 1 vote