Instructions

1. Cut the peppers open and take out the stem, the seeds and every scrap of the white membrane. The membrane is bitter and it dries to a tough flake that stays bitter in whatever you put it in.
2. Dice them at whatever size suits what you cook — small for soups, larger for a pizza topping. Keep one size to a tray, because a small dice finishes hours before a large one.
3. Blanch for two minutes and cool the pieces in iced water if you want them to hold their colour on a long storage. Raw-dried peppers keep more of their sweetness but they fade towards brown over a year, so the choice is colour against flavour.
4. Drain and pat the pieces dry before they go on. Blanched pepper carries water in the hollow of each piece and it will sit there for hours otherwise.
5. Spread the dice one layer deep on mesh with a solid tray underneath. Pepper shrinks to a fraction of its size and small pieces drop straight through once they do.
6. Dehydrate at 57 °C for 11 hours, stirring the trays around once in the middle so nothing stays stuck in the same spot.
7. They are done when a piece is hard and snaps rather than bending, and no piece feels cool or leathery at its thickest corner. Test them cold — pepper skin stays supple while warm and firms up as it goes down.
8. Keep them in an airtight jar in a dark cupboard for a year. Grind only what you need for the next couple of months, since pepper powder is hygroscopic and sets into a solid cake in a jar that gets opened often.