Fluffy Sourdough Donuts (old-fashioned style)

There’s something magical about a donut that’s both fluffy and deeply flavorful-soft on the inside, lightly crisp on the outside, and made entirely with sourdough. These Fluffy Sourdough Donuts are the kind you’ll remember: classic and comforting, yet elevated with that artisan touch.

What truly sets them apart is the sweet stiff starter. It adds a gentle sweetness and structure that gives these donuts their signature pillowy crumb and rich depth of flavor-the kind you just don’t get from commercial yeast.

Whether you glaze them simply or dust them with sugar, these donuts are a slow-morning kind of treat- the perfect blend of old-fashioned charm and sourdough magic.

Why You’ll Love These Fluffy Sourdough Donuts

• The texture is unreal – soft, fluffy, and tender with that classic old-fashioned bite.

• Made with a sweet stiff starter that gives the dough incredible flavor and structure.

• Perfectly balanced sweetness – just enough to let the sourdough shine.

• They feel special – a little weekend project that’s so worth the effort.

What is a sweet stiff sourdough starter?

A sweet stiff sourdough starter is a type of sourdough starter that is characterized by its low hydration and sweetness. Stiff starters typically have around 50% hydration or less, which makes them thicker and more dough-like in texture. The sweetness comes from the sugar and the natural fermentation process of the starter, which produces sugars that give the dough a sweet flavor.

Sweet stiff sourdough starters are great to use in sweet recipes where you don’t want the sourdough tang to overpower the flavor. They also produce a denser texture, which is lovely in sweet recipes. The best part about it, is it still holds all that wonderful gut nutrition!

If you want more information on sweet stiff sourdough starters check out my article here!

How to make fluffy sourdough donuts: step-by-step

BAKER’S SCHEDULE OPTION 1:

• Make the sweet stiff starter the morning of, and mix the dough in the evening (around 7 pm) to bake for the following morning.

BAKER’S SCHEDULE OPTION 2:

• Make the sweet stiff starter the evening before you mix the dough. Mix the dough in the morning, allow to proof, refrigerate overnight, and shape & bake the following morning.

Ingredients

For the sweet stiff starter:

• 20 grams active sourdough starter
• 45 grams water
• 20 grams sugar
• 90 grams of all-purpose flour

Tip: there will be 5-10 grams of extra sweet starter to account for any sticking to the sides of the jar. It is better to have more than less!

For the donut dough:

• 150 grams (2/3rd cup) of sweet stiff sourdough starter (from above)
• 65 grams (1/3rd cup) of sugar
• 120 grams (1/2 cup) of whole milk
• 57 grams (1/4 cup) of unsalted butter (melted)
• 1 large egg
• 5 grams (1 teaspoon) vanilla extract
• 300 grams (2 & 1/2 cups) of all-purpose flour
• 5 grams (1 teaspoon) of salt
• 4-5 cups of avocado oil for frying (vegetable oil can be used)

For the glaze:

• 240 grams (2 cups) of powdered sugar
• 50 grams (1/4 cup) of milk
• 1 teaspoon of vanilla extract

The glaze is optional. You can use powdered sugar, cinnamon sugar, or keep them plain!

Equipment:

• Mixing bowl
• Food scale
• Baking sheet
• Parchment paper
• Donut cutter (or a glass jar with a 3-5 inch opening)
• Rolling pin
• Slotted spoon
• Shallow pan for frying the donuts

Instructions

Make the sweet stiff starter:

• To a clean jar add 15 grams of active sourdough starter (it is recommended the starter has been fed within the past 12 hours).

• Next, add the sugar and water and stir until it becomes milky.

• Lastly, add the flour and mix until a dough-like ball is formed. You can knead it on a clean surface to ensure all of the flour has been absorbed.

• Cover the jar loosely and allow it to rest for 10-12 hours.

Mix the dough

Ensure your sweet stiff starter has at least doubled in size before mixing the dough.

• In a small saucepan warm the milk and butter together until the butter is melted. Let it cool for 5-10 minutes.

• Once the mixture has cooled, add it to a mixing bowl and whisk in the sweet stiff starter and sugar using a fork or dough whisk. *It is okay if the stiff starter does not fully dissolve, it will break down during kneading.

• Whisk in the egg & vanilla extract, then add the flour and salt, mixing until a shaggy dough forms

• Cover the dough with plastic wrap and let it rest in a warm spot for 30 minutes.

Knead the dough

• After the dough has rested, knead it on a lightly floured surface for 5–7 minutes, or until smooth and cohesive. Use as little extra flour as possible to keep the texture soft and tender.

• Once the dough is smooth and elastic, place it in a buttered bowl and allow it to rest for 30-45 minutes. Perform 1 stretch and fold after its rest for optimal gluten development.

• Let it rest at room temperature (around 68°F) for 8-12 hours or until doubled. If your home is warmer than 72°F, make the dough earlier in the day and refrigerate it overnight to prevent overproofing.

Roll & Shape the Sourdough Donuts

• The following morning ensure the dough has risen. If pulling the dough from the fridge allow it to rest 1 hour to take the chill off.

• Line a baking sheet with parchment paper and spray some non-stick oil on it.

• Place the dough on a lightly floured surface and roll it out to where it is 1/2 an inch thick. Tip: flour your rolling pin to avoid sticking.

• Cut out as many donuts as possible, gathering and re-rolling the dough as needed until it’s all used. This recipe makes about 12 donuts (3.5 inches wide) plus 12 donut holes (munchkins).

• Place each donut and munchkin on your baking sheet and cover with oiled plastic wrap or a large proofing bag for 2-3 hours until they puff up a bit.

Fry the sourdough donuts

• While the donuts rest, cut the parchment paper into squares. This helps transfer them cleanly into the hot oil and preserves their shape.

• Pour about 2–3 inches of oil (4-5 cups) into a heavy-bottomed pot or Dutch oven. Heat to 350°F (175°C) and maintain the temperature between 340–355°F while frying. You can test it by placing one of the munchkins in to see if it floats.

• Carefully lift each donut (parchment and all) and place it into the hot oil. After a few seconds, the parchment will release, use tongs to remove and discard it. Fry 2–3 donuts at a time to avoid crowding the pot.

• Fry each side for about 1–1½ minutes, or until golden brown. Adjust the heat as needed to keep the oil steady.

• Use a slotted spoon to transfer the donuts to a wire rack with paper towels or parchment paper underneath to catch any excess oil. Let them cool slightly before glazing or coating in sugar.

Tips for Perfectly Fried Donuts

• Keep the oil steady: A temperature between 340–355°F is the sweet spot. Too hot and they’ll brown before cooking through; too cool and they’ll absorb excess oil.

• Use a thermometer: Maintaining consistent heat is key to even color and texture, a simple candy or fry thermometer makes all the difference.

• Don’t overcrowd the pot: Fry just 2–3 donuts at a time so the temperature doesn’t drop and each donut has room to puff beautifully.

• Flip gently: Use tongs or chopsticks to turn them once they’re golden on the first side, this helps preserve that lovely round shape.

• Drain properly: Let the donuts rest on a wire rack with paper towels underneath so they stay crisp, not soggy.

Glaze the fluffy sourdough donuts

• In a medium bowl, whisk together the powdered sugar, milk, and vanilla extract until smooth. Add a splash more milk, a teaspoon at a time, until you reach a silky, pour-able consistency.

• Once the donuts have cooled, dip the tops (or whole donut) into the glaze, letting the excess drip off. Place them on a wire rack so the glaze can set beautifully.

• For the munchkins, toss them in a bowl of powdered sugar while still slightly warm, the sugar will cling perfectly for that soft, sweet coating.

• The glaze is completely optional! These sourdough donuts are so flavorful on their own that they’re just as lovely plain, or simply brushed with melted butter and dusted with sugar.

• These donuts are best enjoyed the day they’re made, that’s when the texture is at its fluffiest. If you have leftovers, store them in an airtight container at room temperature for up to 1–2 days. To refresh, warm them briefly in the microwave or oven just until soft again.

More sweet sourdough recipes

• Sourdough Cinnamon Rolls (soft & not too sweet!)
• Sourdough Brioche by Hand (no mixer needed!)
• Sourdough Hawaiian Rolls (soft & sweet!)
• Sourdough Sugar Cookie Bars