Bring to a boil the water with lemon zest, cinnamon and cloves in a large pot. Lower heat, then stir in cherries and sugar. Simmer until cherries are tender, about 10 minutes. Take out the lemon zest, cinnamon and cloves.
Beat salt and flour into the sour cream until smooth. Stir in vigorously one cup of the hot soup.
Pour the sour cream mixture into the pot and stir very well. Bring to a quick boil, lower heat and simmer for 5 or 6 minutes, until the liquid thickens a bit. Add the wine (optional).
Remove from heat, cover with lid and leave to cool. Chill the soup completely in the refrigerator, still covered to avoid a skin to form. Serve cold with a dollop of sour cream.
If you find them, use fresh sour cherries. Frozen sour cherries can be used as well, but avoid can or jarred ones.