Has Your Soda Lost Its Pop?

Has your diet drink lost its flavor because it was on the grocery shelf too long?

Pepsi-Cola Co. seems to concede the possibility with a test it began in the Omaha, Neb., area last spring that stamps a “freshness date” on containers of Diet Pepsi, the nation’s fourth-best-selling soft drink.

A Pepsi spokesman said the sweetener aspartame, used in many diet soft drinks, loses sweetness in two to six months on the shelf, which can affect the taste.

Coca-Cola is reportedly studying sales in Omaha and has started printing freshness labels.