Air Fryer Japanese Sweet Potato Chips (Honey Butter)
Japanese sweet potatoes are the ones with purple skin and pale yellow flesh — drier, starchier, and noticeably sweeter than the orange American kind. Sliced paper-thin and cooked in an air fryer with a little honey and butter, they turn into crisp, faintly caramelized chips that taste like a cross between a potato chip and a sweet potato.
There’s one thing about this recipe that nearly made me throw the first batch away, so I’ll say it up front: they come out of the air fryer floppy. Not crisp at all. You let them cool for a few minutes and they turn crunchy on the plate. If you don’t know that’s coming, you’ll assume you’ve failed and cook them until they burn — which is exactly what I almost did.
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Why You’ll Love This Recipe
- No deep-frying. Chips normally mean a pot of oil. Here it’s 5 g of butter and a spoon of honey for the whole batch.
- One sweet potato makes a bowl of them. 150 g of sweet potato is genuinely cheap for a snack this good.
- Sweet and salty at once. The honey caramelizes at the edges and the pinch of salt makes it taste like a proper snack rather than a dessert.
- Nothing to clean up. One bowl, one basket.
What is a Japanese Sweet Potato?
Satsumaimo (さつまいも) is the Japanese sweet potato: reddish-purple skin, pale cream to yellow flesh, and a dense, dry, chestnut-like texture. It’s not the same vegetable as the orange sweet potato most Americans picture, and the difference matters here.
- Japanese (satsumaimo) — drier and starchier, higher in sugar, holds its shape. Crisps up properly.
- Orange sweet potato — much wetter and softer. It will work, but it takes longer and tends to go chewy at the center rather than snapping.
If you have an Asian grocery near you, look for the purple-skinned ones — often labeled Japanese sweet potato, satsumaimo, or by variety names like beniharuka or beniazuma. Any of them work.
Ingredients (Serves 3)
| Ingredient | Amount | Notes |
|---|---|---|
| Japanese sweet potato | 150 g / about 5 oz | Roughly one small one; skin on |
| Honey | 20 g / about 1 tbsp | |
| Unsalted butter | 5 g / about 1 tsp | |
| Salt | A pinch | Don’t skip it |
Four ingredients, and two of them are honey and butter in quantities you’d barely notice. The salt is doing more work than it looks like — without it these taste flat and cloying rather than like a snack.
Equipment
Two things matter. The first is an air fryer that holds a steady temperature around 165°C (330°F) — I use a COSORI TurboBlaze air fryer, and this is the third thing I’ve made in it that genuinely beats the stovetop version, after yaki onigiri and chicken wings.
The second is a mandoline slicer, and it isn’t optional. These need to be about 1 mm thick and — more importantly — evenly 1 mm thick. Slices that vary in thickness burn and stay soft in the same basket. A knife will not get you there, and I say that as someone who cooks a lot. Mine is an ordinary Japanese plastic mandoline; any cheap one works.
How to Make Air Fryer Sweet Potato Chips
Step 1: Slice 1 mm Thin
Wash the sweet potato and leave the skin on — it crisps beautifully and gives each chip a purple rim. Run it over the mandoline into a bowl of water, aiming for 1 mm. Use the guard; sweet potato is hard and the blade is not forgiving.
Step 2: Soak for 5 Minutes
Leave the slices in cold water for about 5 minutes. This rinses off the surface starch, which is what makes chips stick together and go gummy instead of crisp. The water will turn cloudy — that’s the starch coming off, and it’s the point.
Step 3: Dry Them Properly
Lay the slices out on paper towels and pat the tops dry as well. This is the step that decides whether the recipe works. Any water left on a slice turns to steam in the basket, and steam is the opposite of what you want. Take the extra minute and dry both sides.
Step 4: Melt the Honey, Butter, and Salt
Put the honey, butter, and a pinch of salt in a heatproof bowl and microwave for about 40 seconds at 600 W, until the butter has melted and you can stir it into a thin, runny glaze. It should pour, not sit in a lump — if it’s still thick, give it another 10 seconds.
Step 5: Toss Gently
Add the dried slices to the glaze and turn them over until each one has a thin coating. Be gentle — raw 1 mm slices tear easily, and a torn chip cooks unevenly. Tongs work better than a spoon here.
Step 6: Lay Them in the Basket
Spread them out as flat as you can. Some overlap is unavoidable with a batch this size — that’s fine, you’ll separate them partway through. What you want to avoid is a thick pile in the middle.
Step 7: 165°C (330°F) for 16 Minutes, Shaking Partway
Cook on the air fry setting at 165°C (330°F) for 16 minutes. Partway through, pull the basket out and separate any slices that have stuck together, then carry on.
You’re aiming for about half of each chip turned golden brown. That sounds darker than feels comfortable, but pale chips stay soft — the browning is where the crispness comes from. My machine’s preset wanted 160°C and I nudged it to 165°C, which browned them more reliably.
Step 8: Let Them Cool — This Is the Important Part
Straight out of the basket they will be limp and bendy, and they will not look like chips. Leave them alone for a few minutes. As the residual moisture escapes and the honey sets, they go crisp on the plate.
Almost everyone’s instinct at this point is to put them back in for longer. Don’t — that’s how you get burnt chips that are still chewy in the middle. Wait first, then judge. If they’re genuinely still soft after five minutes of cooling, give them another two or three minutes in the machine.
Tips and Variations
- Even thickness beats thin thickness. A consistent 1.5 mm works better than a mix of 0.5 mm and 2 mm. This is the whole argument for the mandoline.
- Dry them properly. If these come out soft and pale, wet slices are the most likely reason.
- Don’t fill the basket deep. Two thin batches beat one crowded one. Piled slices steam each other.
- Salt only, if you prefer. Skip the honey and use a teaspoon of neutral oil with a good pinch of salt for a plain, savory chip.
- Add cinnamon to the honey butter for something closer to a dessert.
- Keep the skin on. It crisps well, adds color, and peeling 1 mm slices is a waste of a good sweet potato.
What to Serve It With
These are a snack rather than part of a meal — the Japanese category is oyatsu, the afternoon something-sweet that sits between lunch and dinner.
- Green tea or hojicha. The bitterness works against the honey.
- As a snack alongside air fryer chicken wings if you’re putting drinks and small plates on the table.
- In a lunch box as the sweet corner, next to something savory like yaki onigiri.
Storing
Once completely cool, keep them in an airtight container at room temperature for two or three days. Cool them fully before the lid goes on — trapped steam turns a crisp chip soft within the hour, and this is the most common way people ruin a good batch.
Don’t refrigerate them; the humidity in a fridge softens them faster than the counter does. If they do lose their snap, two or three minutes back in the air fryer brings them most of the way back.
Frequently Asked Questions
What temperature and time for sweet potato chips in an air fryer?
165°C (330°F) for about 16 minutes, with the slices cut 1 mm thin and the basket shaken partway through. Lower and slower is right for chips — at 200°C the edges burn before the centers dry out. Remember they crisp as they cool, so don’t judge doneness straight from the basket.
Why are my air fryer sweet potato chips not crispy?
Usually one of four things: you judged them before they cooled, the slices were still wet, they were cut unevenly, or the basket was too full. Cooling is the most common one by far — they’re supposed to be floppy when they come out.
Do you need to soak sweet potatoes before air frying?
For chips this thin, yes. Five minutes in cold water removes the surface starch that makes slices stick together and go gummy. You must then dry them thoroughly, or you’ve traded one problem for a worse one.
Can I use orange sweet potatoes?
Yes, but expect a different result. Orange sweet potatoes hold much more water, so they take longer and are more likely to end up chewy rather than snapping. Slice them slightly thinner and dry them especially well.
Do I have to peel them?
No — leave the skin on. It crisps up well, holds the chip together, and the purple rim is half the reason these look good. Just wash the potato properly first.
Can I make these without a mandoline?
Honestly, not well. The recipe depends on slices being both thin and even, and hand-cutting a hard sweet potato to a consistent 1 mm is beyond most people, myself included. A vegetable peeler gets closer than a knife if that’s all you have, though the slices come out narrow.
Air Fryer Japanese Sweet Potato Chips (Honey Butter)
Ingredients
Method
- Wash the sweet potato and leave the skin on. Slice it 1 mm thin on a mandoline straight into a bowl of cold water. Even thickness matters more than thinness – uneven slices burn and stay soft in the same batch.
- Soak the slices in the cold water for 5 minutes to rinse off the surface starch. The water will turn cloudy.
- Lay the slices out on paper towels and pat both sides dry. Any water left on them turns to steam in the basket and stops them crisping.
- Put the honey, butter, and salt in a heatproof bowl and microwave for about 40 seconds at 600 W, until melted and runny enough to pour.
- Add the dried slices and turn them gently with tongs until each one is thinly coated. Raw slices tear easily, so be careful.
- Spread the slices out in the air fryer basket as flat as you can. Some overlap is fine; a thick pile is not.
- Cook on the air fry setting at 165C (330F) for 16 minutes, pulling the basket out partway through to separate any slices that have stuck together. Aim for about half of each chip turning golden brown – pale chips stay soft.
- Tip them onto a plate and leave them for a few minutes. They come out of the basket floppy and crisp up as they cool. Do not put them back in before they have cooled, or they will burn.
