fozziebayer, while there is no set-fast rule for this, based on what ssamjang sauce is made of and its similarity to other condiments, we can make a good guess. ssamjang's main components are fermented soybean paste and red pepper sauce, along with other smaller amounts of brown sugar, onions, garlic, sesame oil and green onions. many of my korean friends go through it so fast that none of them has ever run into this problem so they are unable to give a testimonial, but I would treat it similar to ketchup: i wouldn't use it after it has been there for more than 6 months. however, use your senses: one of the most distinguishing things about ssamjang is its signature deep red color. give it a look and a quick taste...if something seems off, its better to toss it than get sick. I included a photo of the sauce below as a color reference (and also to show what it is for those who haven't encountered ssamjang before). hope this helps!