Growers, shippers, wholesalers, and retail outlets all have a stake in getting the best possible fresh market grapes to consumers. Many consumers are just now discovering muscadines, and making their first experience a positive one is key their coming back to buy more. Harvesting and selling under ripe grapes, for example, is a practice that leads to a less positive experience for consumers who may tend to assume that all grapes are like that. If they already know what muscadines should taste like that they may assume they can’t ever find good grapes at the store.
Basic storage recommendations: Keep between 35 and 41 F. Major causes of post-harvest loss are softening and decay (botrytis, anthracnose) all of which are suppressed at lower storage temperatures. Chilling injury (discoloration) can become noticeable on bronze grapes after 10 days at 34 F.
Here are some resources
USDA Grading Standards for Muscadines (webpage)
USDA Grading Standards for Muscadines (pdf file)
The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks (USDA) includes information on individual foods and plant stocks as well as lots of more general information about post-harvest biology and technology. It’s a 792-page document (pdf). We have extracted the Muscadine specific pages here.