the best, creamy, fresh-tasting butter imaginable. Try it, I know you'll be crazy about it!
We do this with that 42% smietanka (double cream) from Biedronka. Remember - this is quite important - to wash it thoroughly twice between your fingers, squeezing it under a tap otherwise the maslanka in it will make it go off quickly. Add some salt if you like that or want to make it last a bit longer. You can do it with a hand held blender, or in a food processor.
You're right, it really is the best, creamy, fresh-tasting butter imaginable.