Pickling is an ancient method of food preservation dating back to 3rd century BC China. Unfermented pickles are typically put into an airtight jar with acid and flavorings and heated to kill any potential bacteria on the fruit or vegetable that may cause illness or spoilage. After a few days, the pickles are ready for consumption. The biggest concern about pickled foods is Clostridium botulinum. Clostridium botulinum is a microorganism that produces a fatal toxin in anaerobic environments with a pH above 4.6. The toxin causes botulism, a serious paralytic illness that can be fatal and is considered a medical emergency.