Two days. Want to eat a good taste of grapefruit, need to be left for two days to deacidification, so it is needed two days. Wild grapefruit is native to Central America, first discovered in Barbados, South America, about 1750, introduced to the United States in 1880, about 1940 around the introduction of China grapefruit is also called grapefruit, Zhu Luan. Because the fruit is dense, clustered, like grapes hanging in bunches, it is called grapefruit