How long can you keep tomato sauce in the refrigerator?
Once opened, tomato-based sauces are only good for five days to
a week. Don't wait for the mold to form. In many cases, you won't
see the mold in the sauce after five days, but it actually could be
there. Some mold produce toxins that can be harmful, so why take
the risk? Mold grows in very wet environments. What promotes the
mold is the high moisture content. No amount of cooking will kill
the toxins. So, to be safe, you need to throw it away.