The type of vinegar you select to soak cucumbers really depends on the results you want. Cucumbers go in vinegar to create a fermented pickle, a quick refrigerator pickle or a light salad or condiment. Vinegars vary in assertiveness, and some, such as herbed or fruit, come with flavors that may not complement your recipe. When settling on a type of vinegar to use, consider how you'll serve the cucumbers and the other ingredients you plan to add.
White vinegar is probably the most common vinegar to use. It offers nothing but pure acidic flavor, so you can add any fresh herbs or pickling spices. Use it when making jarred pickles or quick refrigerator types. White wine vinegar is also an option but more appropriate for cucumber salads, as it has a more delicate flavor.
Apple cider vinegar offers a slightly sweet flavor along with strong acidity. It works well for pickles -- either canned or quick -- and in cucumber salads. It's less assertive than plain white vinegar.
Red Wine Vinegar
Red wine vinegar also has more delicate flavor that enhances a salad, but is a little too light for fermented cucumbers. The vinegar is usually made from fermented red grapes but has no alcohol content. It'll color your salad a pleasingly light, pinkish hue.
Rice Wine Vinegar
Rice wine vinegar is the lightest of all and complements Asian flavors. Slice cucumbers as thinly as possible using a mandolin, and mix with a splash of fish sauce, minced ginger and garlic, and sesame oil for a quick condiment for salty stir-fries or Thai satay. Rice wine vinegar comes plain, or seasoned with roasted garlic, basil or citrus. Any work as a complement to cucumbers, depending on what other flavors are in your salad. Rice wine vinegar is too delicate for canning pickles and it may even be too light for refrigerator pickles.
Herbed vinegars can have any number of additions, including fresh tarragon, dill and thyme. Fruit, garlic, green onions and peppers also flavor vinegar that is appropriate for cucumbers -- the type you choose really depends on your tastes. Syrupy balsamic vinegar can be part of a vinaigrette that tastes good on cucumbers, but it's too heavy and rich for a long-term soak.