Actually with grapes you do not need to make an invert syrup...which is water, sugar and citric acid. Grapes naturally have invertase, the enzyme that helps convert the sugar. You can dissolve sugar in just enough water so that it is clear so it mixes into the must easier.
If making non-grape wines it is recommended you make an invert syrup. If you do not do so, the ferment will still occur but with a bit more stress.
Motto: quel che sara sara