be sure to use seedless grapes. picking seeds out of your teeth is never fun.
want to make it even lighter? use cool whip frozen whipped topping instead of sour cream.
you can use grapes of just one color or you can use green and red grapes.
keep the brown sugar and pecan topping separate until ready to serve to keep them from getting soggy.
this is best enjoyed chilled but you can serve it at room temperature.