I was surprised how simple this is! Start to finish it took about 35 minutes, and would be less the next time since I know what to do. The only ingredients are organic whipping cream. I used 1 pint, but 1 quart will make 1 lb of butter.
Finally it breaks down into cottage-cheese looking
blobs. The butter will stiffen and you will see it getting wet. When it clumps and watery milk pools form in the bottom, turn off mixer.
Using a rubber spatula, press butter to squeeze out "butter milk". Carefully pour out as much as possible. It will not be thick like the kind you buy, but can be used to bake or drink. Now "wash" the butter with ice water. Pour 1/2 cup ice water over the butter and keep pressing it against the side of the bowl. Repeat this several times until the water runs fairly clear. This will stop the butter from spoiling and it firms it up .Make sure water is ice cold.
Continue kneading butter and squeezing liquid out. I used my hands in the end and patted it and squeezed.