Vinegar is the preservative and flavoring agent in most pickles. What kind you use depends on the color and flavor you want to have in the pickled product. Most pickle recipes call for distilled vinegar. This is the clear, colorless vinegar made by fermenting grains. It has a mellow aroma, tart acid flavor, and does not affect the color of the light-colored vegetables or fruits. Apple cider vinegar, made from fermented apple juice is a good choice for many pickles. It has a mellow, fruity flavor that blends well with many spices. However, it will darken light colored vegetables and fruits. Apple cider-flavored distilled vinegar has the flavor and brown color of apple cider vinegar, but it is a mixture of apple cider flavoring and distilled vinegar. Use it in the same way as apple cider vinegar. Any of these vinegars may be used as long as it has 5% acidic acid. Occasionally you will find four or six percent acidic acid vinegars, but recipe formulation is done with a 5% vinegar so using the 5% vinegar will give you the best results. Do not use wine vinegars or other flavored vinegars when you make pickles, unless you are sure their acetic acid content is 5%. Do not use homemade vinegar when you make pickles because the acetic acid content is unknown and variable. When you make pickles, do not dilute the vinegar unless the recipe specifically directs you to add water. If the flavor seems too tart, add a little sugar. http://www.ext.nodak.edu/extnews/askext/pickrels/463.htm