William A. Mitchell, 92; Chemist, Inventor of Pop Rocks Candy

William A. Mitchell, 92, a food scientist who invented Pop Rocks candy, died of congestive heart failure Monday in a Stockton care home, his daughter said.

Mitchell, who worked as a chemist for General Foods Corp. in White Plains, N.Y., for 35 years until his retirement in 1976, held more than 70 patents, including inventions related to Cool Whip, quick-set Jell-O gelatin and the drink mix Tang.

While working briefly for Eastman Kodak Co., Mitchell helped design a chemical process to develop the color green. During World War II, when tapioca supplies were running low, he developed the tapioca substitute.

Mitchell’s most famous invention was Pop Rocks, the exploding candy that became a cultural phenomenon after it hit the market in 1975. He made the discovery accidentally when, while trying to design an instant soft drink, he put some sugar flavoring mixed with carbon dioxide in his mouth.

For years, Mitchell, who patented Pop Rocks in 1956, fought to dispel the myth that the carbonated candy was deadly if eaten while drinking carbonated drinks.