Instructions

1. Choose radishes that are firm all the way round with no give at the shoulder. A spongy radish is hollow at the centre and dries into a papery ring with nothing in the middle.
2. Twist the tops off and trim the root tail, but leave the skin on. The red skin is where most of the peppery bite sits, and peeled radishes dry into something close to flavorless.
3. Mix the vinegar through a large bowl of water and give the radishes ten minutes in it. The acid loosens the grit that clings to the skin, and it keeps the cut faces from browning while you work through the batch.
4. Slice them thin and even on a mandolin. Radish is dense for its size, and a slice twice as thick takes more than twice as long to finish.
5. Spread the rounds out so none are overlapping and expect the house to smell strongly for the first few hours. That sharp smell is the mustard oil cooking off, and the finished chips are far milder than the kitchen suggests.
6. Dehydrate at 125 °F for around 10 hours. The slices curl and shrink to about half their diameter, which is normal and not a sign that they are done.
7. A finished slice snaps between your fingers with a clean break. Let one cool before you judge it — radish comes off the tray limp and firms up considerably as it goes cold.
8. Keep them in an airtight jar in a dark cupboard for six months. They soften quickly once air gets to them, so a small jar you empty is better than a big one you keep opening.