- How long does an unopened jar of blackberry jam last? The precise answer depends to a large extent on storage conditions -to maximize shelf life, store in a cool, dry area.
How long does an unopened jar of blackberry jam last at room temperature? Properly stored, an unopened jar of blackberry jam will generally stay at best quality for about 2 years.
Is unopened blackberry jam safe to use after the expiration date on the jar? Yes, provided it is properly stored and the jar is undamaged - commercially packaged blackberry jam will typically carry a Best By," "Best if Used By," Best Before, or "Best When Used By" date but this is not a safety date, it is the manufacturer's estimate of how long the blackberry jam will remain at peak quality.
Storage time shown is for best quality only - after that, the blackberry jam's texture, color or flavor may change, but in most cases, it will still be safe to consume if it has been stored properly, the jar is undamaged, and there are no signs of spoilage (see below).
How can you tell if blackberry jam is bad or spoiled? The best way is to smell and look at the blackberry jam: if the jam develops an off odor, flavor or appearance, or if mold appears, it should be discarded.
Sources: For details about data sources used for food storage information, please click here