If you’re a raw fish fiend, tuna is often at the top of the list: smooth and mild with a bit of unctuous fat that melts in your mouth. Its firm, slightly sweet flavor — almost like an incredibly lean beef steak — lends itself beautifully to a super thin carpaccio or tartare, which is slightly chunkier. Interestingly, tuna tartare isn’t just the culinary cousin of the restaurant staple, steak tartare; it was created as a light and temporary replacement. And, while it was only invented in 1984, tuna tartare has become such a ubiquitous appetizer that you may find yourself taking some home in a doggie bag or have some leftover from a dinner party. So, just how long does tuna tartare last in the fridge?
The short and simple answer is one to two days. According to the USDA, uncooked tuna should be kept in the fridge for two days maximum. Even though tuna tartare may have added ingredients — like oil, salt, citrus, or soy sauce — that are considered natural preservatives, tuna tartare has not undergone a full pickling or salt curing, so it is still very much a raw fish and should be treated appropriately. To maximize freshness and quality, the refrigerator should be between 32 and 38 degrees Fahrenheit. When kept in the fridge, it may be wise to remove more delicate ingredients, like avocado and leafy greens, and store them separately to be reunited with the tuna when serving the second time to preserve flavor and texture.
How to keep tuna fresh and know when to toss your tartare
First of all, tuna tartare should always begin with certified sushi-grade fish to ensure it is super fresh, has been handled properly, and is often flash-frozen to avoid the spread of bacteria and remove any existing parasites. Fresh tuna should smell sweet, mild, and slightly salty — like a whiff of the cold sea. The flesh should be bright in color and firm to the touch. Raw tuna or tuna tartare should be stored in the refrigerator in an air-tight container or Ziploc-style bag with air removed to retain freshness and keep it separate from other items that could cross-contaminate.
If your tuna tartare begins to have a sour smell or the flesh turns opaque to gray or brown, it’s time to throw it out. Fish contain a compound, trimethylamine oxide (TMAO), that helps keep their proteins and cellular structure stable when alive, but TMAO breaks down when they die, contributing to the overly “fishy” smell. Because fresh tuna smells so mild and light-briny, even if it has a faint fishy smell or begins to smell like ammonia, it’s probably time to discard it. Furthermore, if the tuna in your tartare becomes slimy or mushy, it has likely gone bad. Bacteria from contaminated fish can cause serious problems, so it’s best not to take the risk — leave it in the fridge for one to two days max. And if you want to keep it for longer, you can avoid bacteria altogether when frozen at zero degrees Fahrenheit or below. When stored properly in the freezer, the tuna will maintain its flavor and texture for a month or more.
