Pour the cream into your clean jar. At least with 2 half-pints, each boy got to pour one in.
OK.............now screw the lid on tightly and SHAKE!!! We took turns shaking, but Mommy did most of the shaking, so be prepared for that. One internet source I read said the whole process should take about 10 minutes. I think it took us more like 15 minutes. One thing that happens is that the cream will get really thick, so thick that it doesn't even sound sloshy when you shake it. I wasn't anticipating this and thought we had messed it up somehow. At that point I poured the mixture into a bowl to see if there were any lumps of butter. Below you can see what it looked like at that point. NOTE: You DON'T need to do this...............just keep shaking past this part...........sorry for the bad photo.
After doing the above, I poured most of the cream back into the jar figuring that if I hadn't goofed it up, perhaps butter was yet to come. I shook for a few more minutes and surprisingly, the cream separated into butter and buttermilk after all!! Yay!! You can tell when this happens because instead of thick cream coating the side of your jar, you will begin to see clear spots and it will sound sloshy again while you shake it. When this happens, take off the lid and you will have a lump of butter with some remaining buttermilk. Below you can see what ours looked like when it was still in the jar. Isn't it cool?
I scooped the butter into a container and salted it lightly. My oldest son drank some of the buttermilk that I poured off it.
Then we spread our very own homemade butter on some warm buttermilk biscuits fresh from the oven. I had put these in to bake right before we started so they would be warm when our butter was ready to spread. Before you get too impressed with my domestic talents, let me assure you that the biscuits were the generic refrigerated biscuits in a tube. They were still SO fabulous when served warm with butter.