If you store the homemade grape salad in an airtight container with a tight-fitting lid, it will keep 2-3 days. The biggest challenge with this salad is that it needs to be refrigerated when it’s not being served. If it sits out very long it can begin to spoil quickly.  Never let the salad sit out for longer than an hour or two unless it is on ice. This will help keep it from spoiling.