The cucumber is a creeping vine that roots in the ground and grows up trellises or other supporting frames, wrapping around ribbing with thin, spiraling tendrils. The plant has large leaves that form a canopy over the fruit.
The fruit is roughly cylindrical, elongated, with tapered ends, and may be as large as 60 cm long and 10 cm in diameter. Cucumbers grown to be eaten fresh (called slicers) and those intended for pickling (called picklers) are similar. Cucumbers are mainly eaten in the unripe green form. The ripe yellow form normally becomes too bitter and sour.
Having an enclosed seed and developing from a flower, cucumbers are scientifically classified as fruits. Much like tomatoes and squash, however, their sour-bitter flavor contributes to cucumbers being perceived, prepared and eaten as vegetables. Still, "vegetable" is a purely culinary term, and there is no conflict in classifying cucumber as both a fruit and a vegetable.
As cucumbers are very sensitive to heat, choose ones that are displayed in refrigerated cases in the market. They should be firm, rounded at their edges, and their color should be a bright medium to dark green. Avoid cucumbers that are yellow, puffy, have sunken water-soaked areas, or are wrinkled at their tips. Thinner cucumbers will generally have less seeds than those that are thicker. While many people are used to purchasing cucumbers that have a waxed coating, it is highly recommended to choose those that are unwaxed, so the nutrient-rich skin can be eaten without consuming the wax and any chemicals trapped in it.
Cucumbers should be stored in the refrigerator where they will keep for several days. If you do not use the entire cucumber during one meal, wrap the remainder tightly in plastic or place it in a sealed container so that it does not become dried out. For maximum quality, cucumber should be used within one or two days. Cucumbers should not be left out at room temperature for too long as this will cause them to wilt and become limp.
