Sides · Air fryer

Perfect Air Fryer Roast Potatoes (Christmas Roasties)

The secret to crispy roast potatoes might be sitting in your cupboard right now. This method uses baking soda during a quick five-minute boil to soften the potato outsides while keeping the centres firm, then finishes them in an air fryer for golden, crackling results every single time.

R By Richard · Adapted from Backyard Chef · Published 10 June 2026
👁 20.7k source views ❤️ 1.2k source likes
⏱Prep 15 min
🌡Temp 190°C
⏲Air fry 20 min
🍽Serves 4
Perfect Roast Potatoes All from this? Christmas Roast Potatoes

Source video by Backyard Chef on YouTube. This recipe was adapted with strict source-fidelity rules and is marked for human review.

A classic Christmas-style roast potato method adapted for the air fryer. Potatoes are peeled, cut to roughly even size, then parboiled briefly with baking soda to soften the outsides while keeping the centres firm. After draining and steam-drying in the pan, they are cooled, sprayed with oil, and air fried in two stages with rosemary, thyme and salt added partway through. The result is a fluffy interior with a crisp, golden crust, using a fraction of the oil of traditional roasties.

Ingredients

Main
  • 1 kgpotatoes, peeled and cut into roughly even chunks
  • 1 tspbaking soda (bicarbonate of soda)
  • oil spray
To finish
  • fresh rosemary, small sprigs (add late)
  • fresh thyme (add late)
  • salt, pinch (add late)

Method

  1. Peel the potatoes and cut them into roughly equal-sized chunks so they cook evenly.

    ~5 min

  2. Put the potatoes in a pan and add cold water to just cover them. Stir in the baking soda. Do not add salt.

    ~2 min

  3. Bring to the boil, then turn down and simmer gently for about 5 minutes. The baking soda reacts with the starch so the outsides soften while the centres stay firm.

    ~7 min

  4. Drain the potatoes well, then return them to the empty pan. Put the pan back on a low flame and give it a gentle shake to drive off the moisture and rough up the edges into a fluffy coating. Do not break them up.

    ~2 min

  5. Tip the potatoes onto a plate or tray and leave to cool. They do not need to cool completely, but the contrast between cool potato and hot air fryer is what gives the crispiest finish.

    ~10 min

  6. Spray the air fryer basket with oil, add the potatoes in a single layer and spray the tops. Cook at 190°C for 10 minutes.

    ~10 min

  7. Open the air fryer and shake the basket to loosen the potatoes. Scatter over the rosemary and thyme, add a pinch of salt and give them another spray of oil.

    ~1 min

  8. Return to the air fryer and cook at 200°C for a further 10 minutes until crisp and golden. Tip into a serving bowl and serve immediately.

    ~10 min

Frequently asked

Why use baking soda in the water instead of salt?
Baking soda raises the pH of the water, which breaks down the surface starch of the potato. That gives you a softer, fluffier outer layer that crisps up beautifully in the air fryer. Salt at this stage just seasons the water and does not help with texture, which is why it is added later.
Do I need to preheat the air fryer?
The video does not preheat. If your air fryer has a preheat setting you can use it for 2 to 3 minutes at 190°C for an even crisper start, but it is not essential as long as the potatoes are cool when they go in.
What are the best potatoes for air fryer roasties?
Floury varieties like Maris Piper, King Edward or Russet give the fluffiest insides and the crispiest outsides. Waxy salad potatoes will not rough up the same way during the steam-dry step.
Can I make these ahead for Christmas dinner?
Yes. Parboil, drain, steam-dry and rough up the potatoes, then cool completely and keep covered in the fridge for up to 24 hours. Air fry from cold using the same 190°C then 200°C schedule, adding a couple of extra minutes if needed.
Why add the herbs halfway through?
Fresh rosemary and thyme will scorch and turn bitter if they cook for the full time at high heat. Adding them at the shake point lets them perfume the potatoes during the final 10 minutes without burning.
Extraction notes (transparency): Potato quantity, baking soda quantity, oil spray amount, salt amount, and quantities of rosemary and thyme were not stated in the transcript. Servings estimated. Temperatures and times are explicit (5 min simmer, 190°C/10 min, then 200°C/10 min). | Second-pass critique flagged 2 fabricated and 3 quantified issues. See critique.issues for detail.