image of sliced purple sweet potato sourdough

Purple Sweet Potato Sourdough

Fall is not just for orange sweet potatoes but for purple sweet potatoes, too. They’re underrated! They’re very purple! They’re magical beauty beings of the underworld! Okay, maybe not. But they’re perfect for a lovely, swirled Purple Sweet Potato Sourdough boule.

These loaves were trendy for a while and I have no shame in bringing them back. I tried to make this recipe as uncomplicated as possible. I know that other recipes for loaves with purple sweet potato can be a bit tedious…but this recipe is simple and reliable. I’ve made it many times without fail.

This is also a pretty mild sourdough bread! So, it’s perfect for children or people who don’t love the tang of sourdough but still want to eat a colorful & naturally-leavened loaf. I love it served with cheese and honey but have also made it into some very delicious bread pudding.

image of crumb shot of purple sweet potato sourdough

Purple Sweet Potato Sourdough: Little details

The timing of this recipe moves like this:

  • Steaming potatoes & making dough for autolyse: 45 minutes
  • Add the mashed purple potato to the dough, then bulk fermentation (overall 4-8 hours or broken down as follows):
  • Rest 1 hour
  • Stretch + fold then rest 1 hour
  • Stretch + fold then rest 1 hour
  • Stretch + fold then rest 1-4 hours (depending on dough environment temp, see below)
  • Shape & set in fridge (cold proofing) for 12-14 hours
  • Remove from fridge & set on counter for 1 hour (preheat oven halfway through)
  • Bake for 1 hour
  • Cool for 2 hours

So, the loaf typically turns out for lunch time if you begin the recipe around 3 or 4 pm.

image of side shot purple sweet potato sourdough

Dough temp!

Dough environment temperature is really important for sourdough fermentation. I like to keep my dough covered at all times and in a proofer (especially in the winter) during bulk fermentation at 80°F. The optimal environment temperature for sourdough dough is around 75-82°F. That may not always be possible, but it’s good to note for your own reference when gauging how long your bulk fermentation takes, or even how long it takes for your sourdough starter to peak.

When I keep my dough environment at 80°F, it takes the minimal amount of time to bulk ferment (4 hours). If your kitchen is much cooler as mine gets in the winter and you don’t have a place like a proofer to keep the dough, you can either create a makeshift proofer in your oven or accept that the dough will take a longer while (not the worst thing in the world!). When sourdough proofs at a colder temperature, it’ll taste milder than being proofed at a warmer temperature.

A few other details

It can be worrisome to add something like sweet potato to a sourdough dough. This is because the moisture content can vary from potato to potato. Purple sweet potatoes are actually not as hydrated inside as say, a garnet sweet potato, and that lower hydration works out great for us. We also combine the mashed potato with some things before adding it to the dough to make sure it is at the proper level of hydration for our dough.

image of mashed purple sweet potat

All of that being said, this dough is still a little different to work with than a normal high-hydration sourdough. It may break a little when you combine the potato mixture into the dough. Usually, this is something to be avoided when working with sourdough but in this case, it works out alright. The dough will also be a little sticky and slimy when you combine, but do the best you can. It doesn’t have to be perfectly combined. It’ll end up looking like a casual swirl when it bakes! So stylish.

If you make this recipe, please comment and rate the recipe below! I love hearing from you all. Also, you can tag me on Instagram @higheralchemybaking with your bake!

image of purple sweet potato sourdough recipe

Purple Sweet Potato Sourdough

This purple sweet potato sourdough recipe is naturally colored with only purple sweet potato! This high hydration dough naturally swirls the potato through folding and airiness. A super soft, fluffy sourdough recipe, this bread won't disappoint!
5 from 2 votes
Prep Time 2 hrs
Cook Time 1 hr
Total Time 21 hrs
Course Appetizer, Breakfast, Lunch, Main Course, Side Dish, Snack
Cuisine American
Servings 1 boule
Calories 90 kcal


  • 5 or 6 quart dutch oven


for autolyse

  • 275g water (ideally 80-85°F in temperature)
  • 80g mature sourdough starter
  • 310g bread flour
  • 50g all-purpose flour
  • 50g rye flour

to add after autolyse

  • 150g purple sweet potato, mashed (you'll need 1 purple sweet potato)
  • 50g water
  • 10g salt
  • 20g bread flour


  • Set a pot with ½ inch deep water over low heat with the lid on. Clean one purple sweet potato, leaving the skin on, and chop into big 2 to 3-inch chunks. Place your chunks on a steamer basket and set the basket inside the pot, being sure that the bottom of the basket does not touch the water. Steam for about 20-25 minutes or until tender when pierced with a fork.
  • After you set the potatoes to steam, in a large bowl or container, combine the 275g of water and 80g of starter by whisking with a fork. Add the bread flour, all-purpose flour, and rye flour and combine thoroughly with your hand. Let sit for 30 minutes to autolyse.
  • When the potatoes are done, remove them from the pot and let them cool for 5 minutes. Afterwards, remove the skins, which should pretty much slide off at this point. Measure out your 150g into a small bowl and mash into a paste with a fork.
  • Add the 50g of water and 10g of salt to the small purple sweet potato bowl and mix with a fork. Then add the 20g of bread flour and very roughly combine, leaving the flour mostly uncombined. This mixture should be semi-dry and crumbly. If it’s noticeably wet, add another 10g of bread flour. Set aside.
  • When the 30 minute autolyse is over, press the dough with your fingertips to flatten it out in its vessel. Spread the potato mixture on the top of the dough. As if you were stretching and folding the dough 5-7 times, pull the dough from the bottom and fold over the potato, rotating the vessel as you work. Then, alternate between gently squeezing the dough and roughly stretching and folding the dough to loosely combine the potato mixture into the dough. It doesn’t have to be fully combined but it should be spotted and streaked with purple/small potato chunks.
  • Cover and set in a warm place to let bulk fermentation begin (about 4-8 hours). Perform 3 stretch and folds at the first three-hour marks. Your bulk fermentation may be longer or shorter if the dough environment runs hotter or colder/if it’s winter or summer. The optimal environment temperature for sourdough dough is around 75-82°F. You can tell when bulk fermentation is done by seeing if there are little bubbles running throughout the bottom and sides of the dough, the dough is about 30% larger and domed.
  • Prepare around proofing basket or line a medium-sized bowl with a rice-floured kitchen towel. Lightly flour a surface and dump the dough out onto it. If bulk fermentation went well, the dough should “burp” and deflate as you dump it out. Shape the dough into a boule and place it seam side-up in your proofing basket or bowl. Fully cover and set in the fridge overnight (12-14 hours) for cold proofing.
  • In the morning, remove the dough from the fridge and set it out on the counter for an hour. Preheat your oven to 450°F a half hour in, then let it the oven and your dough sit for about 15-20 minutes after preheat is over. Sprinkle the bottom of a 5 or 6-quart Dutch oven with cornmeal. Gently flip the dough into it so the floured side is face-up. Score your boule however you wish, cover with the lid, and place in the oven to bake.
  • After 20 minutes, remove the lid from the oven. Bake for another 40 minutes. Remove the bread from the Dutch oven and let cool for 2 hours before slicing.


Your starter should be at its peak when you use it.
You can substitute whole wheat flour for rye flour.
If you don’t have rice flour for dusting, you can use whole wheat flour (I do this all the time).
image of close up purple sweet potato sourdough

Super close-up crumb.

5 thoughts on “Purple Sweet Potato Sourdough

  1. 5 stars
    I made this loaf for thanksgiving -it was fun to see my kids face light up when I cut it open. Mixing the potato into the dough made me a little worried but it came out really nice. thanks

  2. 5 stars
    I was so excited to try another one of your sourdough recipes (all of my previous attempts have been huge hits in the house and with coworkers!)
    I missed out on the vibrant colors because I only had Murasaki sweet potatoes on hand, but the loaf came out so so soft – the perfect pillow for any and all thanksgiving leftovers!
    Now on my grocery wish list are purple yams so that I incorporate the color wow-factor – thank you so much for this creative and fun recipe!!

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