Making butter was NOT on my list, and in fact not even in my random thoughts. However, I DO buy cream to drink in my coffee... not artificial dairy creamer, not half and half (which is all ultra-pasteurized anyway), but real, honest-to-God cream.
A few days ago I was in a small store and happened to look in the cooler. I know there is a small Jersey Dairy started in the area about a year ago, but I hadn't seen many of their products around. This store had pints of their Jersey Cream for $1.49, and since I know Jerseys have a higher butterfat content in their milk, I decided to try it and bought 2 pints. The containers had no expiration date but I bought them anyway.
This morning when I put cream in my coffee, I thought the cream was about to go south. Even though it wasn't spoiled, it did have a few thicker chunks floating in it. So to make a long story short, I decided to make butter rather than lose a full pint plus the tad left in the first pint.
I left them on the counter to come to room temp for 3-4 hours, and then dumped the contents into a large bowl. All I had to stir was my whisk, since I didn't think there was enough volume to warrant bringing out my big KitchenAid mixer.
Within 30 seconds, the fat globules had started to separate from the buttermilk.
In 2 minutes it started looking like butter, simply stirring with the whisk.
In 3 minutes I had a substantial mass that was too hard for the whisk so I got out a spatula. You can see a half pint of buttermilk I had already drained off, standing in front of the bowl, and a little more buttermilk in the bowl.
Within 4 minutes I had to switch to a sturdier tool, a wooden tool I use for icing cakes. Not shown is taking it to the sink and running cold water over it while stirring/mashing to rinse more of the buttermilk out. I'm not sure I got it all. The best thing to do would have been to spread it out thinly on a marble slab except I don't own one. If all the buttermilk is not rinsed away, the butter will sour and spoil soon.
At his point I mixed in a pinch of kosher salt to taste, put it in a small container, and weighed it. My pint plus the remaining 1/8 pint in the first container made over half a pound of butter! I'm sure 2 full pints would have made a full pound of butter... and I paid only $1.49 per pint.