Cooker vs. Canner Question

In our last blog post, Urban Gardens and Pressure Cooking, we had a commenter ask us a very important question:

OneOfTheseThingsIsNotLikeTheOthers said...

RE: "You can use a pressure canner for cooking, however you CANNOT use a pressure cooker for canning." Why not? Is it size? Or pressure?

We wanted to share our answer with all our blog readers for we feel that this is definitely something that everyone who is pressure canning and/or pressure cooking should know.

 One part of it is size (it would be very hard to fit certain jars in a cooker). However, from our experience, what information we can find, and customer stories, the main part of not being able to can in a pressure cooker is that the pressure cooker heats up and cools faster than a canner which does not allow adequate processing time for your cans to go through the proper process, which could ultimately lead to problems with botulism in your canned goods.

Hope this information helps anyone who was wondering about this rule of not canning in a pressure cooker.