Potato doughnuts are the easiest doughnut I make: mash leftover potatoes, stir them into a flour dough with baking powder, cut or drop the rings, and fry at 375F until golden. Learning how to make doughnuts with mashed potato takes about 30 minutes of hands-on work plus a rest in the fridge, and the dough is forgiving enough that a first batch usually comes out well. There is no yeast, no deep-frying proofing box, and nothing that has to be finished same-day.
The whole trick is getting the mash and the flour balance right. Too wet and the dough sticks to everything; too dry and the rings fall apart in the oil. Get that part right and the rest is just temperature control.
Table of Contents
- What You Need
- Step-by-Step: How To Make Doughnuts With Mashed Potato
- Common Mistakes
- Frequently Asked Questions
- How do I make doughnuts with mashed potato that stay soft and tender?
- How do I fix doughnut dough that is too sticky to roll?
- What temperature should I fry potato doughnuts at?
- How do I tell when the doughnuts are done frying?
- Do potato doughnuts expand when you fry them?
- Can I freeze doughnuts made with leftover mashed potatoes?
- Conclusion
What You Need
This makes 14 to 16 doughnuts plus the holes, and it takes about 90 minutes end to end.
The dough
- Mashed potato, 1 cup (about 250 g), cooled to lukewarm. Boiled, roasted or leftover all work. Yukon Gold or russet are fine; skip waxy or very starchy-without-moisture potatoes, which turn gluey.
- All-purpose flour, 1 1/2 to 2 cups (190 to 255 g), plus extra for dusting. Start at 1 1/2 cups and add by the spoonful.
- Baking powder, 2 teaspoons. Baking soda works too, but then you need buttermilk or sour cream for the acid. Baking powder is the simpler path.
- Sugar, 3 tablespoons, plus more for cinnamon sugar.
- Salt, 1/2 teaspoon. Do not skip it. It is the difference between a doughnut and a sweet roll.
- Ground nutmeg, 1/4 teaspoon, optional but traditional. Cinnamon also works.
- Egg, 1 large
- Milk, 1/3 cup (80 ml), or buttermilk or sour cream for a tangier crumb.
- Melted butter, 2 tablespoons
- Vanilla extract, 1 teaspoon
The equipment
- Rolling pin and a 3/4-inch thickness guide (a ruler works, or cut a strip of cardboard to that height)
- Doughnut cutter. No cutter? A wide glass makes the ring and a bottle cap or champagne flute makes the hole.
- Heavy pot or Dutch oven with 2 to 3 inches of neutral oil, or a deep fryer
- Deep-fry thermometer. This is the one tool worth owning; guessing is the single biggest cause of greasy doughnuts.
- Slotted spoon or spider, cooling rack or paper towels, and a wire rack over a baking sheet
The word doughnut and the word donut mean the same food, and this recipe shows up under both spellings. In Pennsylvania Dutch cooking they are called spudnuts, which is the name most worth knowing.
Step-by-Step: How To Make Doughnuts With Mashed Potato
Two shaping methods work with the same dough. The rolled-and-cut version gives you even rings that hold their shape, and the drop version skips rolling and cutting entirely and is the easiest route for a first batch.
| Method | Prep | Fry time | Result |
|---|---|---|---|
| Rolled and cut | 20 min plus 30 min rest | 90 to 120 seconds per side | Even rings, crisp edge, best for batches |
| Drop from a spoon | 5 min | 60 to 90 seconds total | Rugged, thick, the easiest option |
1. Prepare the mashed potato and get the leavening ready
Cook about 300 g of potatoes until a knife slides through with no resistance, then mash until completely smooth with no lumps. A lump of potato means a lump of doughnut, and a lump in the oil is a popped piece of hot oil, so take the extra minute.
Leftover mashed potatoes work, and refrigerated is fine. Cold or chilled mash straight from the fridge can go into the dough as-is; if you prefer, warm it gently in a saucepan first. The one thing to avoid is mash so wet that it holds no shape on the spoon. If yours is loose, cook it down with the lid off for a few minutes.
2. Mix the dough until it is soft and slightly tacky
Whisk the flour, baking powder, sugar, salt and nutmeg in a large bowl. In a second bowl, beat the egg with the milk or buttermilk, then stir in the melted butter, vanilla and the cooled mashed potato.
Add the wet mixture to the dry and stir with a spoon until no dry flour is visible, then knead in the bowl with clean hands for about 30 seconds. The dough should feel soft, a little sticky, and it should hold its shape when you squeeze it. If it is unworkably wet, add flour a tablespoon at a time. You are aiming for somewhere between 1 1/2 and 2 cups of flour total, and the potato moisture is what moves you across that range.
3. Knead briefly, cover, and rest the dough
That is the entire knead. Potato starch does most of the tenderizing work here, so unlike a yeast doughnut you do not need five or ten minutes of kneading to develop gluten. A heavy knead is what makes these dense.
Wrap the dough and refrigerate it for at least 30 minutes. An overnight rest works too and makes the dough easier to roll in the morning. Use it slightly chilled, not straight from a cold fridge, because cold dough cracks at the edges when you roll it out.
4. Roll and cut the doughnuts, or skip the cutter
Flour the counter lightly, pat the dough down, and roll it to 3/4 inch thick. Thicker than that and the centers cook before the outside browns; thinner and they soak up oil and go flat in the fryer.
Cut rings and holes, or use a wide glass for the ring and a bottle cap for the hole. Wipe the glass and cap with a light film of oil first so they release cleanly. Roll the scraps into a second pass, but stop once they get tough or the doughnuts start to bake unevenly.
For the drop method, just wet two spoons, scoop heaped teaspoons of dough, and slide each one into the oil at 375F. They spread into rough rounds, which is exactly the look Fat Tuesday spudnuts are known for. Because you skip the rolling step, keep the dough a shade thicker than 3/4 inch in the bowl. Whichever route you pick, this is where most of how to make doughnuts with mashed potato goes wrong, so measure the thickness rather than eyeballing it.
5. Fry until golden at 375F (190C)
Heat 5 to 6 cm of canola, peanut, or vegetable oil to 375F (190C) and confirm it with a thermometer. A pot half full of cold doughnuts is also the classic thermometer: if a small piece sizzles immediately and steadily, you are close.
Lower 4 to 6 rings in at a time. Use a spider or slotted spoon and lower them away from you so they do not slosh oil, and never drop them from height. Cook 90 to 120 seconds per side, turning once with the spider, until both sides are an even golden brown with no pale patches.
Crowding drops the oil temperature, and that is the number one reason potato doughnuts come out soggy and greasy. If the temperature falls below 360F (182C) while your batch fries, pull one out, wait for the oil to recover, and cook in smaller batches.
Drain on a rack over a paper towel, not in a pile. Steam trapped underneath is what softens the bottom crust.
6. Glaze and serve
Doughnuts are best glazed or dusted while still warm. For a sugar glaze, stir 1 cup (120 g) of confectioners’ sugar with 2 to 3 tablespoons of milk and a few drops of vanilla until it ribbons off the spoon, then drizzle while the doughnut is hot. For cinnamon sugar, mix 1/2 cup sugar with 2 teaspoons cinnamon and toss the warm doughnuts in a shallow bowl. For a simple vanilla icing, melt 2 tablespoons butter, stir in 3/4 cup confectioners’ sugar and 1 tablespoon milk, and spoon it over. Let a glazed doughnut sit 10 minutes before moving it or the glaze slides off.
Common Mistakes
Almost every disappointing potato doughnut traces back to one of four things: sticky dough, oil that is too cool, dough that is too thick, or a fryer that is too full.
| Symptom | Cause | Fix |
|---|---|---|
| Dough sticks to the counter and tears | Wetter mash than the flour can absorb | Add flour one tablespoon at a time and knead 15 seconds between additions until it only just stops sticking |
| Rings fall apart in the oil | Dough was under-floured, or the mash was lumpy | Add another 1/4 cup flour and mix until the dough holds together cleanly in your hand |
| Doughnuts are soggy or greasy | Oil below 360F, or too many doughnuts added at once | Fry 4 to 6 at a time and hold 375F (190C) the whole time |
| Outside dark, center raw | Rolled too thick | Roll to 3/4 inch and cut at that thickness |
| Exterior browns too fast | Oil above 390F | Lower the heat and let the oil settle back to 375F before the next batch |
| Shapes come out lopsided | Doughnuts dropped from height or pushed into oil off-centre | Lower each ring flat with a spider, then release the handle slowly |
| Glaze runs off the doughnut | Doughnut was glazed after cooling, or the glaze was too thin | Glaze within 10 minutes of draining, and add another tablespoon of confectioners’ sugar |
Storage and reheating
Plain or sugar-coated doughnuts keep best the same day. After that, store them in an airtight container at room temperature for up to 24 hours, or refrigerate for 2 to 3 days. The refrigeration window follows standard leftovers guidance for cooked potatoes, which is 3 to 4 days at or below 40F (4C).
For longer storage, freeze in a single layer on a sheet, then move to a bag or box where they keep for up to 2 months. Thaw at room temperature and revive them in a 350F (175C) oven for 5 to 7 minutes, or in an air fryer at 340F (170C) for 3 to 4 minutes. A microwave leaves them soft and chewy, which is fine for the first minute and disappointing after that.
Glazed doughnuts freeze less well than plain ones, since the glaze goes tacky on thawing. Sugar-coated or dusted ones freeze beautifully.
Frequently Asked Questions
How do I make doughnuts with mashed potato that stay soft and tender?
Two things control the texture. First, mash the potatoes completely smooth, because any lump you leave becomes a lump in the doughnut. Second, add flour gradually and stop as soon as the dough stops sticking, usually between 1 1/2 and 2 cups for 1 cup of mash. Potato starch keeps the crumb moist for days, so a doughnut made this way rarely goes stale.
How do I fix doughnut dough that is too sticky to roll?
Add flour in small portions rather than trying to fix dry dough later. A tablespoon at a time, kneading 15 seconds between each, gets you to a soft dough that still holds its shape in your palm. Chilling the wrapped dough for 30 minutes also firms it up considerably. If the dough is sticky because your mash was wet, cook that mash down first rather than loading the dough with flour.
What temperature should I fry potato doughnuts at?
375F (190C) is the number to hold. It is where the outside browns before the inside soaks up oil. Some heritage Pennsylvania Dutch recipes use 365F (185C) for a paler, less sweet result, which is worth trying but is not the default. More important than the number is keeping it there, since crowding drops the temperature fast and that drop is what causes greasy doughnuts.
How do I tell when the doughnuts are done frying?
Look for an even golden brown on both sides with no pale patches, which for a 3/4 inch ring takes 90 to 120 seconds per side. When you lift one out, the underside should sound crisp as oil drains off it. Do not trust colour alone on the first try, so pull one early and split it to check the centre before you cook the rest of the batch.
Do potato doughnuts expand when you fry them?
Not much. There is no yeast in this dough and only a modest amount of baking powder, so the expansion is minor compared with a yeast doughnut. What actually happens in the oil is that the dough sets and stops drinking in fat, which is why holding the temperature steady matters more than the rise. A dough that puffs noticeably usually has too much baking powder in it.
Can I freeze doughnuts made with leftover mashed potatoes?
Yes, and this recipe is one of the best uses for a holiday batch of leftover mash. Shape the doughnuts first, fry them, cool them completely, then freeze in a single layer on a sheet before moving them to a bag or box. They keep for up to 2 months and reheat best in a 350F (175C) oven for 5 to 7 minutes. Plain and sugar-coated freeze better than glazed.
Conclusion
Start with the mash, not the flour. Cook or rescue your leftover potatoes, mash them completely smooth, cool them, and measure the flour into the bowl before you start so you are adding it a tablespoon at a time instead of guessing. That single habit is what keeps the dough soft instead of sticky or crumbly.
Then fry one test ring before you shape the batch. Ninety seconds a side tells you whether your oil is holding temperature and whether your dough thickness is right, and it costs you one doughnut instead of fourteen. Once that one comes out evenly golden, roll, cut and fry the rest, and glaze them while they are still warm. Learn how to make doughnuts with mashed potato once and you will reach for it every time the fridge has a lonely bowl of mash in it.
