How long does peanut butter and jelly mixture keep in the fridge?

Answer 1

Peanut butter by itself in a sealed container can keep a year in a cupboard. Mixing it with jelly can introduce airborn bacteria, but bacterial growth on both the peanut butter and jelly would be largely limited to surfaces in contact with air--growth inhibited by sugar content. Spread on bread, the bread would likely mold before the mixture.

Quite a few factors influence the amount of time a mixture might be stored, such as the temperature of the refrigerator, what else is stored in it, and the environment in which the mixture was prepared. Some jellies develop mold faster than other varieties. I suspect the amount of time a jelly can be stored would be the leading consideration--it would go bad before the peanut butter.

Another factor concerns how much mold one can tolerate. Many times you can scrape developing mold off the top and the product beneath remains fine. Its flavor may not be affected by the surface mold. So a deep container could survive longer than a broad, shallow container in the same environment.

One last factor concerns how frequently the container is accessed. If you open it every day, you introduce more bacteria than if you only open it once.

I would estimate a peanut butter/jelly mixture should typically remain good as much as four to six weeks after preparation in the average home kitchen environment. Jelly alone will easily keep several months in a refrigerator.