Coffee percolation process

In a percolation process wherein roasted and ground coffee is loaded into a series of fixed volume extraction columns in a manner such that said roasted and ground coffee exhibits packed bed characteristics and is concurrently contacted with an aqueous extraction liquid, the improvement whereby uniform quality and operating characteristics are obtained at reduced output rates, said improvement comprising loading spent coffee grounds and roast ground coffee into said extraction columns to obtain a packed bed such that said aqueous extraction liquid entering said columns contacts said spent grounds prior to contacting the roasted and ground coffee to be extracted whereby said packed bed characteristics are maintained throughout the extraction process.