According to Official Guinness Records,
The longest distance for a grape thrown and self caught in the mouth is 21.18 m (69 ft 6 in) and was achieved by AJ Henderson (USA) on the set of 'Guinness World Records Unleashed' in San Pedro, California, USA, on 11 July 2013.
For a complete list of 2013 records, please visit 2013 Guinness Records in United States.