Hi Galyna I would add the coffee to the syrup. you can add espresso coffee or instant if your syrup is still hot…the recipe is easy…it’s always equal portion of water and sugar; 1 cup of water and 1 cup of sugar and 1tsp vanilla….bring water and sugar to a boil. Reduce heat and simmer for 5 minutes…if you have instant coffee add it now so it will melt or use espresso…add your vanilla at the end…taste the syrup to determine how much coffee flavour you want!
Sweet-E