Most recipes that call for pumpkin recommend using canned pumpkin puree. There are a variety of reasons for this, including the facts that pumpkin puree is relatively inexpensive, easy to find, convenient to use and very consistent in color, flavor and texture. Having a standard ingredient to recommend helps cookbook authors and recipe writers to help you achieve the desired results with their recipes. You can find both regular and organic pumpkin puree pretty easily these days at both regular and specialty markets. That said, it is also very possible to make your own pumpkin puree and this is a great option or those of us who like to eat squash and pumpkin on a regular basis.
First, start out with a whole pumpkin. It’s best not to have one too large, or it will be difficult to work with. Peel it, slice it open and seed it. Bring some water to a boil on the stovetop. Cut up the pumpkin flesh into chunks and drop it into the boiling water. Cool the pumpkin pieces until they’re tender, exactly the same way you would with potatoes.
Drain and cool the pumpkin pieces, then put them in the food processor. This is the only part where making your own gets tricky. Pumpkin can be fairly fibrous, and canned pumpkin puree is very smooth, so make sure that you process your pumpkin as much as possible. Sometimes, I add back a little bit of water to the puree so that I can process it more easily. I aim to get the consistency close to that of the canned puree (fairly thick, but not dry) so that I know it will work out in the recipes that call for it.
When I make it, I use pumpkin puree within a day or two of making it, storing it in the refrigerator in the meantime.