This page has important tips on pickling safety, ingredients, and supplies.

Very important: Always follow pickle recipes exactly. Altering quantities—especially those of vinegar, vegetables, and salt—can lead to the spread of spoilage-causing bacteria. Scrupulously clean all cooking utensils in hot, soapy water. Rinse thoroughly.

• Use crisp, blemish-free, fresh produce—if possible, within 24 hours of harvest. Wash thoroughly in running water.
• Refrigerate unused produce immediately.

• Use fresh pickling cucumbers, not salad cucumbers. Don’t use waxed cucumbers; wax stops pickling liquid from penetrating the cucumber. Don’t use bruised or damaged cucumbers.
• Cucumbers go bad quickly, particularly at room temperature.
• Remove blossom and stem, and cut about 1/16 inch off the blossom end. The blossom releases enzymes that soften a cucumber.
• Wash cucumbers thoroughly in cool running water. Scrub with a soft vegetable brush to remove any dirt or sand granules.
  

• Use commercial white vinegar with at least 5% acidity. While cider and malt vinegars can add flavor subtleties, they also darken light-colored vegetables.
• You can also use "pickling vinegar" (7% acidity) to make your pickles more sour.

• Use only soft water (water with low levels of minerals and chlorine). Hard water (water with high mineral levels) can lower brine acidity, possibly affecting food safety.
• To soften hard water, boil for 15 minutes, then allow it to stand covered for 24 hours. Remove any surface scum that forms. Carefully ladle the water from the pot without agitating the bottom sediment.

• Use fresh spices , whole, crushed, or ground. Avoid spices stored in your pantry for more than a year.
• Powdered spices can turn pickling liquid dark and cloudy.
• Tie whole spices in a spice bag, made from a large square of cheesecloth. Avoid using colored cloth.
• While premixed pickling spices are available at the supermarket, you may want to make your own mix. Just a few possibilities include cinnamon sticks, bay leaves, chili peppers, black peppercorns, yellow mustard seeds, fennel seeds, whole allspice, whole cloves, whole coriander, fenugreek, dill seeds, turmeric, celery seeds, dill leaves, fresh or dried ginger, horseradish, garlic, and hot peppers.

• Use stainless-steel, glass, or ceramic bowls. For pots and pans, use stainless steel, heatproof glass, or hard-anodized aluminum.
• Avoid containers and utensils made of copper, iron, zinc, or brass (these materials may react with acid and salt).