People have been storing food for centuries before refrigeration, and when you're unloading the groceries, you may find yourself looking at a jar of sweet pickle relish and thinking, "Do I really need to refrigerate this?" The answer is ... yes and no. It depends on how the pickle relish was produced and how soon you'll be using it.
What is Relish?
Relish is a catchall term for any condiment made from chopped vegetables. Relish can be made from green tomatoes, corn, zucchini, cabbage, and just about anything else. However, in North America, relish most often refers to sweet pickle relish, which consists primarily of chopped cucumbers that have been processed with vinegar, sugar and salt. Sweet pickle relish may also be flavored with onions and peppers, and spices like celery seed, mustard seed or dill seed.
Methods of Pickling
The most traditional method of pickling is fermentation. Fermented pickles are made by submerging whole, sliced or chopped cucumbers in salty brine until they develop that classic, old-fashioned pickle flavor. Fermentation produces a high-acid environment, which allows food to be stored without refrigeration. Fermented foods also often contain healthful bacteria that may aid in digestive balance. However, nowadays most store-bought pickles are made by the fresh-pack or quick-process method, where cucumbers are cooked or soaked in vinegar, a process that is faster and easier than fermentation, but the flavor will be flatter, and the pickles will not contain any probiotics. Sour or dill pickle relish can be made either by fermentation or with vinegar, although the vinegar method is much more common for sweet pickle relish.
Storing Sweet Pickle Relish
Fermentation produces lactic acid, which the authors of "Joy of Cooking" call "the ultimate preserver." Fermented foods can safely be stored at room temperature in a cool, dark place, although the vegetables will get softer over time. However, since fermentation feeds on the natural sugars in vegetables, fermented sweet pickle relish will not stay sweet for long. If you want fermented pickle relish that is sweet, you're best off buying or making sour pickle relish and adding small amounts of sugar to taste immediately before consuming. Vinegar-based sweet pickle relish is best stored in the refrigerator for long-term use. All pickles and pickle relishes will be safe at room temperature for short periods of time, such as a weekend camping trip.
Uses for Sweet Pickle Relish
Sweet pickle relish is an American tradition on hot dogs, bratwursts and hamburgers. Add sweet pickle relish to homemade potato salad, tuna salad or egg salad for crunch and zip. Make your own tartar sauce by combining mayonnaise, sweet pickle relish, minced onion and lemon juice. Sweet pickle relish can also be added to homemade salad dressings, such as thousand island dressing.