Tartar Sauce Always Has To Be Refrigerated, And It's All Because Of One Ingredient

Tangy, creamy, and satisfyingly thick, tartar sauce is a condiment in a league of its own ... in terms of flavor, that is. Regarding its fundamental composition, however, tartar sauce is actually structured around another classic condiment. Like yum yum sauce, chipotle aioli, and remoulade, tartar sauce is mayonnaise-based — and that mayonnaise needs to be kept refrigerated in order to stay safe to eat.

Even though tartar sauce's mayo gets dotted with flavorful, acidic elements like chopped pickles or capers and bold additions like shallots, that mayonnaise base is ultimately made from eggs, which are famously perishable. When it comes to ensuring food safety, the FDA calls the temperature range between 41 and 135 degrees Fahrenheit "the danger zone." Here, foodborne-illness-causing bacteria and pathogens like E. coli and salmonella can grow and spawn, turning your flavorful tartar sauce inedible. To stay safe, perishable foods (like a bottle of tartar sauce) shouldn't be left out of the fridge for longer than two hours, per the USDA. If your tartar sauce happens to be sitting on the food table at an outdoor potluck or barbecue on a hot summer day (i.e. it's 90 degrees outside), then that safety window shortens to just one hour. 

This refrigeration rule also applies to dishes that are made with tartar sauce. If you've artfully dolloped a bit of tartar sauce atop each individual hush puppy on a tray, then the tray should only sit out for an hour or two before being popped back in the fridge. 

Tartar sauce is the luscious accouterment to fish 'n chips, fries, or even steak tartare (the elevated French dish from which the condiment gets its name), and with a little temperature control, it can stay luscious. To prevent the growth of harmful bacteria and keep the condiment in peak-quality condition, store tartar sauce at or below 40 degrees Fahrenheit. 

Pro tip: Stashing your sauce bottle in an ice-filled cooler (or in this cute gardening-tool-turned-cooler) can help prolong its freshness at leisurely summertime events. Placing trays of tartar-dressed food atop an ice-filled basin can help food stay fresh for longer, too. Just always be sure to position outdoor food tables in the shade away from direct sunlight. In a pinch, an ice-filled kiddie pool can be the hack you need for serving and displaying chilled foods, as well. 

Even inside the fridge, mayonnaise-based tartar sauce won't last forever. Once it's been opened, store-bought tartar sauce will last in the fridge for up to two months. Homemade versions — like our simple tartar sauce recipe that combines mayonnaise, diced dill pickles, lemon juice, dried dill, and salt — should be used up within a week. If you can't remember how long that bottle has been in the fridge, give it a sniff test. A rancid or sour odor is a probable sign of spoilage, as is visible mold growth or a watery, separated consistency.