Choose 25 slightly unripe plums. Rinse them well. Poke the plums with a needle therefore they will marinate better. Put them into casserole.
Take a medium casserole. Put the sugar, pour the vinegar, and add the cloves and cinnamon. Bring to the boil. Stir all the ingredients until they dissolve. Pour the just boiled syrup into the plums. Put a lid on. Let them sit for 24 hrs.
Pour the syrup off into the caserrole; bring it back to the boil. Cover the plums again. Put a lid on. Let them sit for 24 hrs.
On the third day, put the plums with syrup over heat. As soon as they start to steam, put the plums out with sieve or colander, and set them into glass jar or clay pot.
Let the syrup to boil for some minutes, then cool it slightly, strain and pour it into jars. Cover the plums and let them sit for 24 hrs.
Then seal the jars with plums. Put them into cold place.