Instructions

1. Choose a firm cucumber with small seeds — a Lebanese or a telegraph rather than a big field one. A cucumber is mostly water, and a seedy one is mostly the wrong kind of water.
2. Leave the skin on unless it has been waxed. The skin holds a slice together as the flesh shrinks and it is what stops a chip curling up into a tube.
3. Halve it lengthways and scrape the seed core out with a teaspoon if the seeds are large. That core is the wettest part of the vegetable and contributes almost nothing to the taste.
4. Cut to 1/8" on a mandolin if you own one. By hand the slices vary, and at this thinness that variation is the difference between a crisp and a rubber disc.
5. Salt the slices lightly, leave them on a towel for twenty minutes, then blot them. What comes out onto the towel in that time is remarkable, and every drop of it is time saved in the machine.
6. Lay the slices flat without overlap. They shrink to about a third of their size, so a tray that looks half empty now will not be by the end.
7. Dehydrate at 135 °F for 7 hours. Start checking early, because the narrow slices from the ends of the cucumber finish well ahead of the wide ones from the middle.
8. A finished slice is rigid and translucent and snaps rather than bends. Take one off and let it cool first — cucumber comes off the tray flexible and stiffens within a minute or two.
9. Store them airtight for six months with a desiccant sachet in the jar. If they go floppy on a humid day, a short spell back in the machine restores the snap.