AI Roast Potatoes - created with iterative refinement with AI¶
This started off as a bit of fun. I worked with an AI Assistant using dialogue engineering and iterative refinement to create a receipe for very tasty roast potatoes prepared a day in advance, so that I can just reheat them. The family thought these were the most tasty roast potatoes they had ever had. Note these where much better than my ChatGPT roast potatoes I tried a couple of months ago.
Ingredients:¶
- 1.5kg all-rounder potatoes
- ½ cup oil or goose fat
- 2 tablespoons salt (for water)
- ½ teaspoon baking soda
- Optional: garlic cloves, rosemary, thyme
Day 1 - Preparation:¶
Baking soda: Add ½ teaspoon to the parboiling water. It breaks down the exterior of the potatoes more effectively, creating a better surface for crisping.
For 1.5kg potatoes, use 2 tablespoons of salt
- In about 2 liters (8 cups) of water
- Plus the ½ teaspoon baking soda
The ratio is important because:
- Salt helps break down the potato surface
- Helps season from the inside out
- Works with the baking soda for better crust formation
Par-boiling:
- Peel and cut about 1.5kg of potatoes into evenly-sized chunks (about 2 inches each)
- Par-boil them in salted water until they're just starting to soften at the edges (about 8-10 minutes)
After par-boiling, here's the crucial step for extra crispiness:
- Drain the potatoes in a colander
- Put the lid on the colander and give them a gentle shake to roughen up the edges - this creates more surface area for crispiness
- Let them steam dry for about 5 minutes
While they're drying, we need to prepare the roasting tray.
For the oil preparation:
- Pour a generous layer of oil (about ½ cup) into your roasting tray - goose fat or vegetable oil work well
- Add a few whole garlic cloves and some fresh rosemary if you like
- Put the tray in the oven at 200°C (400°F) for about 5 minutes until the oil is really hot
Here's how to roast them:
- Carefully add the potatoes to the hot oil (they might spit!)
- Turn them to coat in the oil
- Roast for about 40-45 minutes, turning them every 15 minutes
- They're done when golden brown and crispy
To make them even tastier, during the initial roasting:
- Add whole, unpeeled garlic cloves to the oil
- Toss in fresh herbs (rosemary, thyme, or sage work beautifully)
- Season with sea salt and black pepper
- A few tablespoons of semolina when shaking can make them even crispier
For storing and reheating:
- Let them cool completely on a wire rack (this prevents them getting soggy)
- Store in an airtight container in the fridge
Day 2 - Reheating:¶
Just before serving:
- Sprinkle with Maldon salt flakes
- Add finely chopped fresh parsley
- A light dusting of smoked paprika
Oven¶
Here's the oven reheating method:
- Preheat oven to 200°C (400°F)
- Spread potatoes on a baking tray (don't overcrowd them)
- Add a light drizzle of oil or goose fat
- Reheat for 15-20 minutes until hot and crispy
Air fryer¶
- Preheat air fryer to 180°C (350°F)
- Place potatoes in the basket in a single layer
- Spray or brush very lightly with oil
- Heat for 8-10 minutes, shaking halfway through
Food science¶
Baking soda¶
The baking soda works through some interesting food chemistry:
- It raises the pH of the water, making it more alkaline
- This alkaline environment breaks down the pectin (a fiber) on the surface of the potatoes
- The broken-down exterior creates a starchy "slurry" coating
- When roasted, this coating turns into an extra-crispy shell while keeping the inside fluffy
- This is similar to what happens when making pretzels - the alkaline bath is what gives them their distinctive crust!
Temperature control:¶
- Starting with hot oil (200°C/400°F) creates immediate surface dehydration
- This forms a moisture barrier, keeping the insides steamy and fluffy
Potato chemistry:¶
- Higher starch potatoes (like Maris Piper or Russet) create fluffier interiors
- They have less moisture content and more amylose (type of starch)
Surface area optimization:¶
- Rough edges create more surface area for browning
- More surface area means more Maillard reaction (the chemical reaction between amino acids and sugars that creates golden-brown color and complex flavors)
Steam management:¶
- Don't overcrowd the pan - each potato needs space
- Crowding creates steam, which prevents browning and crispiness
- Steam is the enemy of the Maillard reaction
Reheating in an air fryer helps with the Maillard reaction:¶
The air fryer is excellent for the Maillard reaction during reheating because:
- Rapid air circulation removes surface moisture quickly
- The intense, even heat (around 180°C/350°F) is perfect for Maillard reactions
- The confined space helps maintain the high temperature needed
- The food is elevated, so steam can escape from all sides
- This is why air fryers often give better results than conventional ovens when reheating - they create the ideal conditions for continuing the Maillard reaction without making the potatoes soggy.
Here's how to optimize your air fryer for reheating roast potatoes:
Temperature settings:¶
- Start at 180°C/350°F for the first 5 minutes
- Can increase to 200°C/400°F for the final 2-3 minutes for extra crispiness
Loading technique:¶
- Single layer only
- Leave small gaps between potatoes
- Shake basket at halfway point
Adjusting these settings based on potato size or quantity.¶
For larger potato chunks (>2 inches):
- Extend initial heating time to 7 minutes
- Keep at 180°C/350°F longer before increasing temperature
- May need 12-13 minutes total
For smaller chunks (<1.5 inches):
- Reduce initial time to 4 minutes
- Can go to higher temperature sooner
- Total time around 7-8 minutes
For multiple batches:
- Keep first batch warm in oven at 140°C/285°F
- Second batch might cook slightly faster as fryer is fully heated
Common problems¶
If potatoes are soggy:
- Air fryer basket might be overcrowded
- Temperature might be too low
- They might not have cooled properly before refrigeration
If potatoes are dry inside:
- Reheating temperature might be too high
- Cooking time might be too long
- Light spray of oil before reheating can help
If browning is uneven:
- Basket might need more shaking
- Pieces might be different sizes
- Some pieces might be touching
The optimal size and shape for a roast potato¶
Here's the science behind optimal potato dimensions.
Heat distribution physics:
- 2-2.5 inches allows heat to reach the center before the outside burns
- This size creates the ideal temperature gradient from surface to center
- Heat takes about 15-20 minutes to reach the core at 200°C, matching perfect crisping time
Surface area efficiency:
- Angular cuts create more edges for Maillard reaction
- Irregular surfaces provide better oil contact points
- More corners = more crispy bits (everyone's favorite part!)
How irregular surfaces provide better oil contact points¶
Surface tension effects:
- Oil naturally collects in corners and crevices due to capillary action
- Rough surfaces create microscopic "pools" where oil can gather
- These oil-collecting points become intense heat transfer zones
Contact dynamics:
- When you shake the potatoes, irregular surfaces create multiple new contact points
- Each turn exposes different angles to the hot oil
- Rough surfaces have tiny peaks and valleys that hold oil even when turned
How many shakes of the potatoes is optimal¶
For optimal potato shaking, here's the recommended approach:
Initial shake after par-boiling:
- 3-4 gentle shakes with the lid on
- You want to rough up the surface without breaking the potatoes
- Stop when you see a slight floury coating forming
During roasting:
- Turn/shake every 15 minutes (so 2-3 times total)
- Each shake should be gentle but thorough
- Ensure each potato has changed position
Salt water ratio¶
Salt ratio (2 tablespoons per 2 liters) is optimal:
Osmotic pressure effects:
- Creates water that's about 3% salinity
- Strong enough to penetrate potato cells
- Not so strong that it draws too much moisture out
- Balances with internal potato chemistry
Chemical interaction:
- Works synergistically with baking soda
- Helps maintain alkaline environment
- Strengthens the breakdown of pectin
- Enhances starch gelatinization at surface
Optimal basting technique¶
Timing:
- Baste every 15-20 minutes
- Always after turning potatoes
- More frequently in last 15 minutes
- Let oil settle 30 seconds after each turn before basting
Technique:
- Collect oil from corners of pan where it pools
- Squeeze baster gently for even distribution
- Target the drier looking areas
- Aim for edges and corners of potatoes
P.S. Want to explore more AI insights together? Follow along with my latest work and discoveries here: