Should Raisins Ever Be Refrigerated?

Raisins are a pantry staple for those that keep them on hand for a sweet snack or for adding flavor to an oatmeal raisin cookie recipe. While many may keep them in their pantry, do they ever need to be refrigerated, like some other fruits?

As Sun-Maid Raisins likes to remind everyone, raisins are made simply with "grapes and sunshine." Goela Semoet says that this was actually how raisins were first discovered. Ancient Egyptians found wine grapes that had fallen off the vine and dried in the sun. To their surprise, the grapes were not spoiled but tasted sweet. This is because the sugars had become concentrated in this dried form. The process of drying grapes also inspired the Italians to turn raisins into dessert wines.

In addition to sweetening them, drying the raisins also helped preserve them. The Clemson Cooperative Extension says that drying prevents the growth of mold and bacteria by safely removing moisture. According to NDSU, "conditioning" dried fruits is the final step in their processing. This equalizes the moisture content within the batch and further prevents mold and bacterial growth. If dried fruits are alredy well-preserved, do they ever need to be refrigerated?

Raisins need protection from humidity

Yes, under certain circumstances. Still Tasty says that raisins can keep for 6 to 12 months at room temperature as long as they are stored in an airtight bag or container. But if they're in a humid environment, it's best to keep them in the refrigerator instead. Otherwise, the raisins' natural preservation can be compromised by the moisture in the air.

Polygon Group notes that exposing dry foods to humid environments can promote mold growth and spoilage. They recommend maintaining a climate-controlled environment to limit the food's exposure to moisture. The refrigerator is an excellent choice for storing raisins because the moisture and temperature are very well regulated.  In a non-humid environment, they will keep for about the same time in the pantry as in the refrigerator, and there is no risk of spoilage. Freezing raisins is another option that will extend raisins' shelf life for up to 18 months.