Although numerous varieties of cucumbers are grown in home gardens, most supermarkets, greengrocers and farmers markets carry only two basic types: slicing varieties and pickling varieties. Slicing cucumbers are further divided into outdoor and hothouse, or English, varieties. Nearly all of the small, finger-length gherkin cucumbers, used to make little pickles called cornichons, are sold directly to food companies. Occasionally, however, they show up at farmers markets and specialty greengrocers, and pickle makers snap them up.
When choosing slicing cucumbers (the type used in salads and other cold preparations), look for slender, dark green vegetables without yellowing or shriveling. Outdoor varieties should be 8 to 10 inches long and 1 to 1 1/2 inches in diameter at the center. Many are coated with wax, which makes them shiny and helps preserve them. Avoid these if you can, as waxed skin must be peeled, and with the skin goes the vitamin A. Hothouse cucumbers, usually sold wrapped in plastic, should be 12 to 16 inches long and have thin, smooth skin.
Store cucumbers in a perforated plastic bag in the refrigerator for 5 days. Do not put cucumbers in the coldest part of the refrigerator; they prefer temperatures just above 40°F (the temperature of most refrigerators). Sliced cucumbers will keep refrigerated in a covered container for 2 days.
Unless the skin is waxed, there is no need to peel cucumbers. Check for wax by scraping the cucumber with a fingernail. Pickling cucumbers should be scrubbed with a vegetable brush under cold running water to remove loose spines.
Cucumbers may be seeded for stuffing or before slicing crosswise for a salad. To seed a cucumber, first slice the cucumber in half lengthwise. Use a melon baller or spoon to scoop out the seeds and the surrounding pulpy matter. Proceed with stuffing or place the cucumber flat side down on a cutting board and slice crosswise.
For pretty cucumber garnishes, use a vegetable peeler to create alternating stripes of dark green peel and light green flesh, and then slice the cucumber into thin disks.
Adapted from Williams-Sonoma Kitchen Companion (Time-Life Books, 2000).