Store bought dressing will last two to three months after opening if properly stored. The acidic vinegar based versions last longer than ones containing dairy. Homemade Vinaigrette Salad Dressing Recipe How to Make a Basic Vinaigrette My go to summer dressing! Our homemade Honey Dijon Dressing pairs perfectly with just about any salad. We keep a jar in the fridge all summer long its that good. Recipe is on Momsdish.com!