That's a sweet story, K2L. I love grapes myself. I'm afraid I wouldn't be able to stop myself from eating the whole container. I like frozen grapes too for a refreshing summer treat.
The only thing is... grapes are a choking hazard for kids under 5.
I'd be careful to make sure the 20 month old only ever ate them supervised by an adult.
http://www.med.umich.edu/yourchild/topics/choking.htm