I put individual portions of my freshly made purees into plastic sandwich bags, which I store in a sealed, airtight plastic container. In the fridge, they will last between three and five days. If they begin to change color or take on odor, don't use them.
For a large batch of puree, it's best to keep what you will use immediately in the refrigerator and freeze the rest. Purees will last up to six months in the freezer if you store them as described above. Unfortunately, my freezer gives everything the worst freezer burn, so I try to use up my purees right away. Assuming this isn't an issue for you, you can stock your freezer with a lovely array of colorful purees to use whenever you need them! Read more of Jessica's Q&A.