I had never heard of this until this summer, when my aunt mentioned it to me. We then visited a Mennonite shop in the Finger Lakes and when I noticed it in the case, I had to buy some. I didn’t know what it was and did some research when I got home. What I’ve learned is that rolled butter is made from whey cream instead of sweet cream, which is a byproduct of cheesemaking. I also learned that nearly all the rolled butter sold in the US is made in a factory in Wisconsin (Alcam Creamery). The butter is made in a (mechanical) churn, then it is handrolled into logs and wrapped in waxed paper for sale. You can see a video here.
The thing that mattered to me was the taste. Would it be better? I think it does have a slightly deeper flavor than store-bought butter, but it wasn’t enough to knock me off my feet and start ordering this by mail. My next butter adventure is going to be sampling some European butters from the grocery store, because I noticed that the butter in Italy was much better than what we have here, so I want to try some at home.