Keep stirring until you see a thin film on the bottom of the pan, you need to remove as much moisture as possible in this stage. (foodsofourlives.com)
I've never tried making my own puree, but I have friends that have and it tends to make recipes a little more wet since there is so much moisture in the pumpkin. (iheartnaptime.net)
The amount of broth needed for the soup will depend on how much moisture is in your pumpkin, as well as how thick you prefer your soup to be. (reciperebuild.com)