The average shelf life of grocery store coffee can vary depending on factors such as the packaging, storage conditions, and the type of coffee. Generally, pre-ground coffee found in grocery stores can maintain its freshness for about 1 to 2 weeks after opening, provided it is stored in an airtight container in a cool, dark place.
Whole bean coffee has a longer shelf life compared to pre-ground coffee since it retains its flavors and aromas better. When stored properly in an airtight container away from heat, moisture, and light, whole bean coffee from the grocery store can maintain its freshness for around 2 to 4 weeks.
However, it's important to note that these are general guidelines, and the quality and freshness of coffee can deteriorate more rapidly depending on the specific brand, packaging, and storage conditions. For the best coffee experience, it is recommended to purchase freshly roasted coffee from local roasters or specialty coffee shops where the beans are often roasted shortly before being sold.