Ok real quick, I have to tell you the coolest part about cream. Whip it enough and you have butter. Simple enough huh, and no you don't need a butter churn like your grandma used. If you have a mixer, preferably a stand mixer, just pour it in and turn it on high. First it will turn into whipped cream. Whipped cream is the real version of cool whip, (though I do love cool whip), and is great for desserts. But if you continue mixing the cream it will eventually start to break down. For awhile it will look like all you are doing is beating the crap out of it and it isn't going to do anything, and you will wonder if your lights are doing funny things because you will swear that it is starting to turn yellow. (It is). Continue beating the cream and soon you will notice that it has gotten really watery. About the time that the "water" starts splashing out of the bowl you have butter. It all sticks together and comes out in a big blob. It is a little different than what you get in the store, but it is still good. I tell you that making butter is one of the coolest things I have done. I am sure that the feeling of accomplishment by doing it by hand is even greater, but hey we have electricity so lets use it.
A few notes. I am pretty sure that the "watery" stuff is buttermilk....i could be wrong though.
Also, do this in your mixer with a "whip" or "whisk" not a paddle or dough hook, that's ridiculous.