It was in Morrisons in their bakery dept. It’s whipping cream so not as fatty as double. £1 is the normal price, I heard about it on a group on FB but have never managed to get any. Mr Eggy popped in to get his Hovis granary bread flour, no other supermarket sells it and wandered over and there it was. It was 10am so maybe getting there early is the trick. He has a small butter churner, it’s basically a Kilner jar with a hand mixer affixed to the lid. It’s fine for a small amount of double cream but it wouldn’t work with the amount of whipping cream we had. So he put it in the food processor, I suppose a stand mixer or hand mixer would work but it takes a while. Mix it until the butter milk separates from it, about 4/5 mins I think it took. It goes yellow. Separate it and wash the butter in icy cold water. Then pat into shape.we added salt crystals at this stage, you could add other flavours if you wish. We’ve frozen the butter milk for soda bread or scones or even butter chicken. I think the butter can be frozen as it may not last as long as commercial butter. I’ve not tried it as I’m trying not to eat diary until my stomach sorts itself out, but apparently it was good. It’s not cheap to make if you use full price double cream but if you’ve leftovers or get a yellow stickered tub it’s worth the effort.