Those of us who grew up reading books like Little House in the Big Wood learned that churning butter is hard work. Those of us who learned to make our own whipped cream know that it really, really isn't - I know I'm not the only one who, in a moment of inattention, created sweet, vanillay butter. You just need a much smaller amount of cream and an electric device - food processor, stand mixer, hand mixer, or even a rotary eggbeater or a whisk if you want those arm muscles.
I have a dairy hand mixer. It's old, and I haven't actually used it this decade, but it was right to hand. So, I bought heavy cream. The NYT Magazine suggested organic cream, but when I looked at it, it had the same carrageenan as the standard heavy cream and cost more. So. I bought a 1/2 pint of heavy cream. And I let it sit out to get to about 60F (It's purely a guess - my instant read thermometer is fleishig.) And, well, I let it rip. And in about five minutes, it thickened, got to be whipped, made soft peaks, got grainy and broke. In other words, butter. I poured off the buttermilk (delicious) and worked the butter, squeezing out the rest of the butter milk. Now, they said five minutes, but they also used more cream. I squoze until there was no more. It's now sitting in my fridge firming up. No, I did not add salt.
I have no idea what I'm going to do with it - I'm having *chicken* for dinner tonight.
ETA: since I'm NOT fasting today, and dinner isn't even cooking yet, I spread some of *MY* butter on some rye bread. It's sweeter and creamier, but not immensely different than storebought. Next time, I do the culturing thing.