This came to me when I found a couple of half-filled bottles of red wine on the counter. (A rare occurrence at my house) but it does happen. You can do this with a half a bottle of red that's been sitting in your fridge (by the way you should never do that to red wine) for a day or two and just adjust quantities with the amount of wine you have on hand. Feel free to mix and match - a Cab can merry a Pinot.
This is fun for the holidays and floating green fruit makes it so xmas like. —blanka.n