Cut the pumpkins off the vine when the vines are dry and the entire pumpkin is uniform in color. Leave a 3-inch to 5-inch stem. Handle them carefully so you do not damage or mar the rinds. Wash the exterior of the pumpkins with a soapy solution of one part bleach and 10 parts water to make sure there are no disease or fungal organisms on the rind.
Set up a baker's rack in a warm location of 80 degrees Fahrenheit to 85 degrees Fahrenheit with at least 80 percent humidity. If humidity is lacking, put a dish of water in the area close to the rack.
Place the pumpkins on the baker's rack that has been lined with newspaper. Use three layers to five layers of paper to prevent the wire from digging into the pumpkins and making marks on them. The raised racks will allow air circulate around the pumpkins.
Let the pumpkins cure for 10 days. This will allow the rind to harden and any open wounds to seal. After curing, place the pumpkins in a cardboard box lined with newspaper.
Place the box in a cooler location of 50 degrees Fahrenheit. The basement is ideal. Humidity levels need to be between 50 percent and 70 percent to ensure that the fruit doesn't rot.
Spray the exterior of the pumpkin with shellac if they will not be eaten. This gives them a hard coating that helps prevent pathogens from rotting the pumpkin, and slows molds and mildew. It also gives them a decorative shine.