Once you open the jar or tin, you can keep the sauce for about 7 to 10 days. When it comes to the store-bought pesto sold in the refrigerated area, in most cases it has a use-by date on the label. The unopened sauce should retain good quality for maybe up to 5 to 7 days past that date.

What happens if you eat bad pesto?

If it smells like old oil (or rancid0, it's rancid and you should discard it. The same thing holds true if it smells funny. Eating rancid pesto most likely won't make you sick, but it won't taste nearly as good as fresh pesto. ... If your pesto looks and smells okay, give it a taste.

Is it safe to eat expired pesto?

Can you eat expired pesto? Pesto may still be edible after passing its recommended use date. Although the quality may have changed, an unopened jar of pesto may still be safe for the next 1 – 2 months when properly stored. Fresh store-bought pesto might be safe to consume up to 5 days after the use-by date.