Every year families go pumpkin picking in search for the right jack-o'-lantern to ornate their porch. You take the time to carve the best face and cross your fingers hoping it won't rot and mold.
Let's first identify why Jack's scary face turns into a frown after a week or two. The pumpkin guts that you throw out actually keep the vegetable from rotting; without those guts, the pumpkin becomes dehydrated and fungus attacks the inside. It's important when you pick your pumpkin that there are no gouges or bumps, and avoid soft spots! Imperfections can make Jack different from the others, but he will also become the first to be invaded by bacteria.
Try To Buy Fresh
Choosing a pumpkin from the local grocery store is convenient, but not the best decision for Jack's longevity. Picking pumpkins from a farm ensures you that it was harvested near by and still fresh. Pumpkins in grocery stores or bins may have been sitting there for a few days with bruises and have travelled from who knows where.
I did some Internet research and found an interesting pumpkin preservation experiment. Not to spoil the end results, but to make sure Jack stays in tact, you need to hydration your pumpkin and kill off all bacteria and molds by spraying products containing bleach. You could also dump the craved pumpkin in a bucket of water and bleach for a minimum of eight hours, soaking the pumpkin and then sponge it dry after.
Too much work? Purchase a pumpkin preservative and spray inside and outside everyday.
The Unusual Help
You know those tiny bags of seeds that you throw out when you purchase a bag or shoes? They actually have a name and have a purpose. Silica gel packets absorb moisture. So remove the gels from the packet and sporadically embed them; this will take away the excess moisture. Be safe and keep pets and kids away from gels because some gels have a carcinogenic cobalt chloride. You can easily define these gels because they will be colored pink or blue.
Don't over carve! Thin walls cause pumpkins to decay faster.
Don't be a killer! Although you may want to showcase you're craftmanship, placing your pumpkin in direct sunlight is a no-no. You can also place Jack in the refrigerator to avoid temperature changes.
Don't lather your entire pumpkin in glue or vaseline despite the myth that they help.
Let us know how your pumpkin turned out!