A good pickle crunches, giving you a sharp burst of sour pickle flavor when you bite into it. Some homemade pickle, however, don't crunch; they mush. Limp, soggy pickles are usually caused by either a problem with processing, a problem with ingredients, or a problem with the cucumber itself. Adding a few extra steps to your pickling process gives you reliably crisp pickles almost every time.
Crisp pickles start with pickling cucumbers. Unlike slicing cucumbers, which are large and smooth skinned, pickling cucumbers are shorter and have rough skins. You can pickle slicing cucumbers as hamburger slices, and you can pickle immature slicing pickles whole, but both are more likely to get soggy. If you grow your own cucumbers, consult a local master gardener to help you choose a pickling variety that grows well in your area. If you buy your cucumbers, look for unwaxed, short cucumbers with lots of bumps in the skin.
When cucumbers get too big, they get soft. If you start with a soft cucumber, no amount of care during the pickling process gives you a crisp pickle. If you suspect your pickles are too large, slice one open. If the inside is soft or mealy, the cucumber is too large or too old to pickle. If holes are beginning to appear around the seeds, that's also a sign the cucumber is too large. To keep your garden cucumbers from getting to large, pick every day during pickling season.
Cucumbers don't keep well. When they have been in storage too long, they get soft. If you are buying your cucumbers, get them from a farmers' market and can them immediately. If you are pickling cucumbers from the garden and don't have enough cucumbers to pickle immediately, store them carefully. Don't wash them until you are ready to use them. Store them between 45 and 50 degrees Fahrenheit. Make sure they stay as dry as possible. And, most importantly, use them as quickly as possible.
When you are ready to can your pickles, put your cucumbers in ice water while you start preparing the hot water bath and brine. Ice water helps crisp the cucumber, so you are starting the canning process with the crispest cucumber possible.
To prepare your cucumbers, use a soft vegetable brush and wash each cucumber carefully around the stem end. Soil trapped around the stem softens the pickle. Then cut a thin, 1/16-inch slice off the blossom end. The blossom contains enzymes that can also make your pickles soft. Removing the entire blossom removes the enzyme. When preparing the brine, use soft water. Some waters contain minerals that will soften pickles.
Most hot-water-bath canning recipes call for a full rolling boil in the canning kettle. Processing your pickles in boiling water, however, can soften them. To process your pickles, fill the canner halfway with water that is 120 to 140 degrees Fahrenheit. Put the jars in the canner, and fill the canner to 1 inch above the jars with hot water. Heat the water to between 180 and 185 F. Temperatures above 185 F softens the pickles. Temperatures below 180 F allow hazardous bacteria to grow inside the jars. Use this method only when using a tested recipe that recommends it. If you are canning low-salt pickles, the lower temperatures can be hazardous.
Some people use alum or food-grade lime to firm and crisp their pickles. Alum is sometimes used in fermented pickles, but it doesn't help the crispness of quick-process pickles. Lime can give you crisp quick-process pickles, but pickling with lime is time consuming and can be dangerous to use if done improperly. Some old family recipes call for a single fresh grape leaf added to each jar of pickles. A grape leaf can help keep pickles crisp, but, like the other additives, it is unnecessary if you select and handle your cucumbers well.