My husband makes homemade horseradish mayo at home and we store it in a glass jar with a tight twist cap in the fridge, and it's good for a month and sometimes longer. (If I really shouldn't keep it this long, someone please tell me, but the texture stays smooth, it doesn't have any funny smells/tastes, nor does it ever give me any reason to throw away.) So as much as people would worry about the raw egg content, I say just use your physical senses to guide you on whether to keep or ditch it. Besides, the acid (vinegar) denatures protein, so the egg is as good as cooked.
