Fermented pickles are cucumbers that have been placed in a mixture of spices and acids and allowed to age for a period of time. Over the time that the cucumbers are fermenting, different bacteria grow in the liquid and create a unique flavor. They also produce chemicals that help to preserve the pickles. The method used to create fermented pickles should not be confused with another method that uses only vinegar and spices to flavor the pickles, leaving out the entire fermentation period. In grocery stores, fermented pickles are usually easy to identify, because they must be refrigerated to stay fresh.
The process of fermentation requires that good bacteria are present in the fermenting liquid. These bacteria feed on elements in the brine and create lactic acid. This acid has a preservative quality that will help the pickles have a longer shelf life when refrigerated. Lactic acid also imparts a slightly sour taste that is one of the hallmarks of fermented pickles. The fermentation time for pickles can be as little as four weeks or as long as two months.
One of the most important aspects of making fermented pickles is making sure all the vessels being used for fermenting are perfectly clean and sterile. This is because, otherwise, harmful bacteria and other germs could be inside the containers. If harmful yeast or bacteria is allowed to ferment, then the batch of pickles will become rancid, moldy or otherwise inedible. Sterilizing the containers in boiling water can help to reduce the chance of this happening, although hot soapy water also can work in this instance.
The basic process for creating fermented pickles is to pour the brine solution, which contains salt, vinegar and other spices, into a jar that has the cleaned, raw cucumbers in it. The jar is sealed with a sterile lid and then placed in a dark area for four to eight weeks. It is essential that the exact proportions called for in the pickle recipe are followed. If any of the measurements are off, then the environment inside the pickling brine could be off and the bacteria may not grow, meaning the pickles will not ferment. This can result in rotten pickles or pickles that pose serious health risks if eaten.
Once the fermented pickles are completed, the safest way to store them is to can the pickles. This involves first sterilizing a new container. The brining liquid is poured into a pan and heated to kill most of the bacteria, also stopping the possibility of the pickles continuing to ferment. The liquid is strained, added to the new jar with the pickles and then refrigerated. Canned pickles can last in a refrigerator for up to six months.