Purple Sweet Potato Sourdough Sandwich Loaf

I really am in love with Stokes purple sweet potatoes. I’ve used them to make purple sweet potato pancakes like latkes. And this week I made mashed purple sweet potatoes and banana. There was one baked sweet potato leftover from that night, so I used it for this purple sweet potato sourdough sandwich loaf.

I’ve previously made another sweet potato sourdough that is a variation of my cheater sourdough (i.e. it uses a bit of commercial yeast). That one has bacon. Yes, bacon. This purple sourdough sandwich loaf is not as decadent, and it’s much prettier.

a loaf of pink-tinked purple sweet potato sourdough with three slices and a bread knife.
a cutting board with a cut purple sweet potato, a whole potato, and a knife
three purple sweet potatoes on foil with one sliced open to show the purple flesh

Tips and tricks for this recipe

– The amount of water or flour you will need will vary based on your levain (I use a 100% starter – equal amounts of water and flour – in a small volume levain), your sweet potato, etc. Please don’t think of my amounts as law. You want to end up with a sticky ball of dough at the end of mixing.
– I bake bread in order to have an easy-to-slice loaf of bread for sandwiches. But you can shape this in any way that makes you happy. I’m jealous of all of those pretty boules out there.

a mixing bowl with flour and mashed purple sweet potato
a boule of purple sweet potato sourdough bread dough

FAQs about this purple sweet potato sourdough

Why do you use yeast in your sourdough bread?

I make a cheater sourdough bread using ¼-1/2 teaspoon of instant yeast so that I can finish the loaf in one day. Feel free to omit the commercial yeast if you are a purist.

Why do you add salt after all the other ingredients?

I have acquired the belief, true or not, that you shouldn’t add salt to bread until well after the process has started for fear of direct salt effect on the yeast and bacteria (that whole osmosis and cell wall thing). This is probably overkill, but it is something I always do (i.e. delay adding salt).

What is that loaf pan you use?

It is the Italian Bread Loaf pan from Emile Henry.

Can I substitute other sweet potatoes for the purple sweet potatoes?

Yes, and please see my note above re: water and flour. Purple sweet potatoes are slightly drier than white- and orange-fleshed sweet potatoes, so you might need to adjust.

Are these purple sweet potatoes the same as yams?

I wrote a few sentences a week or so ago to answer this question about the difference between purple sweet potatoes and purple yams (ube). Spoiler: the only thing they share in common is their color!

How to store sourdough bread?

If we are not going to eat the loaf within a few days, I slice the bread and put the slices in a freezer bag in the freezer to extend the life of the loaf.

What do you make with your sourdough discard?

The King Arthur website has a great list of sourdough discard recipes. The crackers have been my favorite so far.

a ceramic loaf pan with the unrisen purple sweet potato sourdough loaf

Related recipes

Check out other breads for sandwiches.

Or here are a few of my other recipes for purple sweet potatoes:
mashed purple sweet potato with banana
purple sweet potato pancakes (latkes)
loaded purple sweet potatoes

a plate with a turkey sandwich made with a pink colored bread.

Purple Sweet Potato Sourdough

5 from 1 vote
Category: Bread
Cuisine: Unspecified
Total Time: 9 hours
Servings: 12 slices
Calories: 187kcal
Stokes purple sweet potatoes provide inspiration for this beautiful and soft pinkish purple sweet potato sourdough sandwich loaf.
Print Recipe


  • 1 cup mashed purple sweet potato
  • 1 cup (125 grams) whole wheat flour
  • 3 cup (375 grams) bread flour plus more as necessary
  • ¼ teaspoon instant yeast optional
  • 127 grams levain (sourdough starter)
  • 1 cup (250 grams) lukewarm water plus more as necessary
  • 2 tablespoons maple syrup
  • 1 teaspoon salt
  • butter or oil for greasing, if using a loaf pan


  • In a large bowl, mix the sweet potato, flours, yeast (if using), levain/starter, water, and maple syrup, initially with a spoon or spatula and then by hand. The mixture should be somewhat sticky, so add small amounts of flour or water as needed. Cover with plastic wrap and set aside for 20 to 30 minutes.
    1 cup mashed purple sweet potato, 1 cup (125 grams) whole wheat flour, 3 cup (375 grams) bread flour, ¼ teaspoon instant yeast, 127 grams levain (sourdough starter), 1 cup (250 grams) lukewarm water, 2 tablespoons maple syrup
  • Add the salt to the bowl and knead until incorporated. Form into a ball and lightly oil the bowl. Cover with plastic wrap and put in a warm location – the microwave or a 85 to 90°F oven works well here.
    1 teaspoon salt
  • Every 20 to 30 minutes for 2 to 3 hours, reshape the dough into a ball. Do not stress if it's shorter or longer than 20 to 30 min intervals. Because of the stickiness, you might need to wet your hands for the first one or two of these. It should double in size and get more pliable.
  • Shape and let rise in a greased bread loaf baker or dutch oven. I really love my bread loaf baker, which gives a great crust and that loaf shape that I need. Let it rise until doubled in size – how long will depend on whether you were using a well-fed or un-fed starter and/or the amount of commercial yeast.
    butter or oil for greasing, if using a loaf pan
  • Preheat the oven to 450°F at least one hour before baking.
  • Bake at 450°F in the dutch oven/baker for 30 min, then reduce the heat to 350°F, remove the lid and bake about another 15 minutes. When done, the internal temperature of the loaf should be 190 to 195°F, and it will sound hollow when the bottom of the loaf is thumped.
  • Let cool for at least one hour before cutting.


Bread can be stored at room temperature for a few days, although it will be best within a day or two of baking. The cooled bread can be sliced and frozen for a month or so.


Calories: 187kcal | Carbohydrates: 39g | Protein: 6g | Fat: 1g | Saturated Fat: 0.1g | Polyunsaturated Fat: 0.2g | Monounsaturated Fat: 0.1g | Sodium: 203mg | Potassium: 163mg | Fiber: 3g | Sugar: 4g | Vitamin A: 4485IU | Vitamin C: 5mg | Calcium: 24mg | Iron: 1mg
Love this recipe?Mention @Uglyducklingbakery or tag #uglyducklingbakery!

What’s next?

If you make this purple sweet potato sourdough, please leave a comment or rating here.

Follow uglyducklingbakery on your favorite social media platform.

Looking for inspiration?

Sign up to get recipes full of kitchen tips and tricks.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating

This site uses Akismet to reduce spam. Learn how your comment data is processed.