All varieties of cucumbers can theoretically be used as salad cucumbers, also known as slicing cucumbers, or as pickling cucumbers. However, some varieties are much better suited for one type of preparation than the other. Regardless of whether a cucumber is to be sliced and eaten as is, or pickled and then consumed, the most important qualities are that it is fresh and crisp, not overripe and soft.
Certain varieties of cucumbers have been bred specifically for use in pickling. By using these varieties, the home pickling enthusiast will end up with a crisper and more flavorful result. If growing these vegetables at home, be sure to select seeds that are labeled as "pickling" or "good for pickling" on the seed packet. Good choices include Pioneer, National Pickling, Saladin, Bush Pickling, County Fair Hybrid, Liberty Hybrid, Ballerina, Boston Pickling, and Eureka Hybrid. For salad cucumbers, recommended varieties include Sweet Slice Burpless, Salad Bush, Straight 8, Burpee Hybrid, Sweet Success, Poinsett, Indio, and Dasher II.
Pickling cucumbers typically have thinner skins than the salad type, allowing for the vinegar, brine, or other pickling solution to better penetrate the skin and flavor the meat. They are short and squat, instead of long and lean. Pickling cucumbers also usually have "warts," the little bumps on the skin that are the trademark of the classic dill pickle; salad cucumbers usually have much smoother skins. Good pickling varieties will also have fewer seeds as well, unless they have been left too long to ripen.
Cucumber varieties bred for pickling are typically gradient in color: dark green at the stem end that fades to light green at the blossom end. Salad types will be a more uniform dark green from tip to tip. The belly is the side where the growing vegetable was in contact with the soil before harvest. A pickling cucumber will typically be a lighter green in that area than a salad cucumber.
As a general rule, salad and burpless varieties do not make outstanding pickles, except for relishes or bread-and-butter pickles where a softer texture is desirable. Garden-grown cucumbers should be refrigerated immediately upon harvesting, and at least within 24 hours. Refrigeration will minimize moisture loss, which is the key to crispness. Store-bought pickling cucumbers should always be refrigerated as soon as possible in order to increase the likelihood of producing a crispy, crunchy pickle.