Because it is cubed not a puree. The issue comes when it is mashed or pureed. To can the mashed or pureed pumpkin, you would need a commercial canner for safety measures. Has to do with the thickness of the mash/puree. It is best to freeze. Anyway that is what I have always been told so have never tried. Also since I am only going by passed down info, I could be full of dog doots!
Edit to add:
*shakes finger at Worth*
Don't do it! I can hear you thinking from here >,< Yes I said I could be full of dog doots. Hold yourself back . . .
