Cola by citric or other isolated acids. Coca-Cola's recipe is maintained as a corporate trade secret. A variety of different sweeteners may be added to cola, often partly dependent on local agricultural policy. High-fructose corn syrup (HFCS) is predominantly used in the United States and Canada due to the lower cost of government-subsidized corn. In Europe, however, HFCS is subject to production quotas designed to encourage the production of sugar; sugar is thus typically used to sweeten sodas. In addition, stevia or an artificial sweetener may be used; "sugar-free" or "diet" colas typically contain artificial sweeteners only. In the 1940s, Coca-Cola
Coca-Cola Black Cherry Vanilla product's sale, the percentage of drinks bought from Coca-Cola and its variants that was Black Cherry Vanilla Coke was 4%, compared to 9% for Coca-Cola with Lime and 3% for Diet Black Cherry Vanilla Coke compared to 7% for Diet Coke with Lime, 13% for the Caffeine free Colas, 13.5% for Coke Cherry and Diet Coke Cherry, and 26% for Diet Coke. With low sales figures, and the return of Vanilla Coke (now Coca-Cola Vanilla) in the summer of 2007 in the United States, Black Cherry Vanilla Coke was discontinued. Coca-Cola Freestyle fountains have a variation in the form of