Methods of acidic warewashing are disclosed. The compositions can include other materials including surfactants and chelating agents, and are preferably phosphorous free. Methods of using the acidic compositions in combination with alkaline compositions are also disclosed. Exemplary methods include using the acidic compositions together with other compositions, including alkaline compositions and rinse aids employed in an alternating alkaline/acid/alkaline manner. The methods also include acidic compositions that serve multiple roles.