Purple Sweet Potato Muffins with a touch of rosemary, are a warming and delicious treat. The combination of creamy melting cheese, the subtly sweet, sweet potato and the fresh herbs, is out of this world! And what’s so interesting is that with baking soda in the mix, the purple potatoes turn green!
Yet another thing they didn’t teach me in culinary school — baking soda makes purple potatoes turn green! Seriously folks, I opened the oven door and my jaw dropped. I was expecting to see beautiful, bright purple sweet potato muffins., and instead I saw these not unattractive, but not beautiful, interesting green creations!
Yep, turns out purple sweet potatoes worked as a natural green food coloring! Bizarre, right!?
Why do purple potatoes turn green when mixed with baking soda?
Apparently the anthocyanin that provides the purple color, reacts with baking soda — or anything alkaline — and turns the resulting mixture green, or blue-green.
As you know, I’m a chef, not a scientist, so here’s a bit more on that. 😉
Here’s the deal, it doesn’t matter what color they are because they’re so delicious! They have a light, soft texture with a creamy potato vibe. Add to that, melting Gruyère, which has a wonderful nutty taste, and the lovely earthy, pine-like flavor of rosemary.
They’re amazing served warm, with or without butter. And they’re divine along side cozy brisket stew.
For this recipe I used the gorgeous Stokes Purple Sweet Potatoes from Frieda’s. Here are a couple more of my favorite recipes in which they are the star — and purple!
Chile-Lemon Roasted Purple Sweet Potato Fries
Purple Sweet Potato–Soup with Spicy Chile Oil
Okay, so getting back to the green. . . . think of the possibilities for Saint Patrick’s Day!
Whatever their color, I hope you love these Purple Sweet Potato Muffins with Rosemary!
In this recipe, the combination of creamy melting cheese, the subtly sweet, sweet potato and the fresh herbs, is out of this world
*Please note that the prep time does not include cooking and mashing the potato, which should take about 15 minutes. (See notes)
- 1 cup peeled cooked, and mashed purple sweet potato (from about 1 small-medium sized potato -- see notes)
- 1/3 cup buttermilk
- 2 large eggs
- 1/2 cup olive oil
- 1 tablespoon granulated sugar
- 3/4 teaspoon sea salt
- 1 1/3 cup all-purpose flour
- 1 1/2 teaspoons baking soda
- 1 cup Gruyère cheese, divided
- 1 tablespoon plus 1/2 teaspoon fresh rosemary, finely chopped
- 2 tablespoons unsalted butter, softened to room temperature
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Preheat the oven to 350 degrees F, and adjust a rack to the center. Line a muffin tin with 12 paper cups. Set aside.
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In a large mixing bowl, combine the mashed sweet potato (see notes on how to mash the potato), buttermilk, eggs, oil, sugar and salt. Mix until smooth -- you can use an electric mixer if that's easier.
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Add the flour and baking soda and mix only until it's incorporated.
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Fold in 2/3 cup of the grated cheese and the rosemary.
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Fill each paper muffin cup about 3/4 the way up with the batter.
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In a small bowl, mix the softened butter with the remaining 1/3 cup of grated cheese and then evenly distribute this on top of each batter-filled cup.
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Bake in the preheated 350 degree F oven until the muffins are set and becoming golden, 20 to 25 minutes.
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Let them cool for at least 10 minutes before serving.
To mash the potato: Peel and then cut the potatoes into large chunks. Place them in a steamer over boiling water and cover. Steam until the potatoes are fork tender, about 10 minutes. Remove them from the steamer and use a fork to mash them immediately. Let them cool to room temperature before using them in the recipe.
This is not a sponsored post. Frieda’s sent me Stokes Purple Sweet Potatoes for recipe testing and I love them!
Who knew? They still look great.
Thanks Cathy — I never know these things! 🙂
Oh noes! LOL But hey, this also works for Christmas, yes? 😉
We also found that when cleaning up, once in a while, hitting the purple sweet potatoes with soap turns it BLUE…then green. Isn’t chemistry fun?
We probably should make a note of that on our product page…
So interesting, Oakley! I love them whatever color they turn! Though I think they’re the most gorgeous raw. Gorgeous! Thank you for sharing them with me!
Acid to make them purple, soda to make them green- sort of like red cabbage
Terri, I’m thinking this year’s science fair. 😉 We miss you guys! xoxo
If purple sweet potatoes are anything like purple asparagus then perhaps the culprit is heat as much as it is acid. As with many purple foods, purple asparagus turns green (or greenish) when cooked – though the flavor remains the same. Actually I shouldn’t say purple asparagus turn green, but cooking does cause a chemical reaction in the anthocyanins which reveals the green chlorophyll beneath the purple anthocyanins that was always there. GREG
Cool, Greg. You more a scientist than I am! 😉 xo
I keep trying to read through On Food and Cooking, so I can learn the science, too! It’s bedtime reading, but it puts me to sleep way too quickly! Thanks for the lesson Greg.
Valentina, these are so festive and perfect for the holidays!
Thanks, Lauren! That’s so funny about it putting you to sleep quickly. 🙂 Happy Holidays! XOXO
Cooking can be so much fun! That’s a huge plus in addition to keeping everyone feed and happy! Great post Valentina. I could use one of these scrumptious muffins for my lunch today!
Thanks, Deb. Truthfully, I almost laughed when I opened the oven door. Fun, it is. Happy Holidays to you and yours! XOXO
What a creative recipe. I love how you took the savory route on the muffin. It’s truly a great idea. Awesome.
Thanks so much! 🙂 Happy Holidays!
Valentina – these sound amazing! I think I will make them for Mardi Gras. They have all the right colors…