Cook the syrup. Pour water into a saucepan or jam bowl and bring to a boil. Add sugar and cook over medium heat for 5-10 minutes until the sugar is completely dissolved.
Add the berries. Pour the viburnum into the hot syrup and cook for 5 minutes after boiling. Then remove from heat and leave to cool for 12 hours. After that, put the container with the jam back on the fire, bring to a boil and turn off the heat.
Place the jam in jars. Transfer the hot jam into dry sterilized jars and close with clean lids. Turn the jars with jam upside down until completely cool. Store the viburnum jam in the refrigerator or a cool cellar.