Start by washing the pumpkin and removing the stem. Remove the stem by breaking it off or cutting off with a knife.
Cut the pumpkins in half and remove the seeds and strings. Now cut the pumpkin pieces one more time so the pumpkin is now quartered. Add pumpkin pieces to the slow cooker skin side up. (If using a very large pumpkin you can cut into smaller pieces)
Add 1 cup of water over the pumpkin.
Cover and cook on HIGH for 4-5 hours or on LOW for 6 hours.
With tongs, remove the pumpkin pieces onto a baking sheet to cool. Cool for at least 20 minutes or longer.
When the pumpkin is cool enough to handle put one piece in the palm of your hand and use a spoon to scoop out the flesh of the pumpkin. Discard the skin.
Put the pumpkin flesh into a blender or a food processor. Add 2 tablespoons of water. Place the lid on, and pulse on high until smooth.
Place in containers and refrigerate for at least 4 hours if you are making a pie with it.
Video
Notes
What kind of pumpkins should I use to make puree?
Pie pumpkins, often called sugar pumpkins are great for pie making as they are smaller and sweeter.
Large pumpkins can be used for pumpkin puree as well. Do not use pumpkins that have been carved and sitting out as they can be moldy. The puree won't be quite as sweet but you can offset that with a touch more sugar in your recipe.
How to store fresh pumpkin puree?
Place the puree into containers, jars or ziplock bags. I do not recommend water bath canning pumpkin puree, it is too thick to can correctly.
Store in the fridge for up to 5 days or freeze for up to 6 months.