Perfect Crispy French Fries

Step 1: Peel the potatoes. Cut them into 6 mm / 1/4-inch fries using a serrated knife.

Step 2: Keep the cut fries submerged in a bowl of water to prevent them from browning while you cut the remaining potatoes. They do not need to soak beyond this.

Step 3: Transfer the potatoes to a colander and rinse under tap water for 15–20 seconds.

Step 4: Put the fries in a large pot with 2 litres/quarts of cold tap water, the vinegar, and salt. Bring to a boil over high heat, then immediately reduce the heat to low so the surface ripples gently rather than bubbling vigorously. Cook for 10 minutes. Carefully lift the fries into a colander with a slotted spoon; do not pour them into the colander, as they may break.

Step 5: Spread the fries on 2 tea-towel-lined trays and leave them to steam-dry for 5 minutes.

Step 6: Pour oil to a depth of 3 cm / 1.2 inches into a pot at least 10 cm / 4 inches high. For safety, leave at least 7 cm / 3 inches between the oil surface and the rim of the pot.

Step 7: Separate the fries into 3 batches for cooking.

Step 8: Heat the oil to 205°C / 400°F over medium-high heat.

Step 9: Using a slotted spoon, carefully lower one-third of Batch 1 into the oil. Wait 10 seconds, add another third, wait 10 seconds, then add the remaining fries in the batch.

Tip: Add the fries in stages to help prevent the oil from bubbling up too high.

Step 10: Fry for 50 seconds, moving the fries once or twice. Lift them out with a slotted spoon and spread them in a single layer on 2 paper-towel-lined trays. They will still be pale and soft.

Step 11: Repeat the first fry with Batches 2 and 3, using the same staged method. Make sure the oil is back at 205°C / 400°F before cooking each batch.

Step 12: Leave the fries to cool for 30 minutes.

Step 13: Line a large bowl with paper towels for draining and tossing the fries.

Step 14: Heat the oil to 205°C / 400°F. Fry half the fries for 4 minutes, moving them around twice, or until golden and crisp. Drain them in the lined bowl, then repeat with the remaining fries.

Step 15: Sprinkle the fries with salt or your chosen seasoning, toss, and serve.

Tip: The fries are already salted from cooking in salted water, so season lightly at first, taste, and add more if needed.

Step 16: The fries stay crispy even once cool.