Condiments and oils
Watson and Nielsen both agree that opened condiments such as ketchup, maple syrup, salad dressing, mayo, mustard, pickles, salsa and relish can be placed either on shelves inside the fridge’s doors or at the front of fridge shelves. Most condiments contain natural preservatives in the form of vinegar, sugar or salt, so they don’t require the coldest territory inside the fridge. Oils such as nut, flax and sesame are fine here, too. Typically, ketchup, relishes and jams can last up to six months in the fridge; maple syrup and mustard, up to a year; and mayo, two to three months.