Whytt's treatment of the stone by limewater and soap became obsolete. Japanese "konnyaku" is made by mixing konjac flour with water and limewater. Dry maize grain is soaked and cooked in an alkaline solution, usually limewater. Limewater is the common name for a saturated solution of calcium hydroxide. Limewater is the common name for a dilute aqueous solution of calcium hydroxide. Limewater is used in a process known as lime softening to reduce water hardness. When used for this purpose, limewater is usually referred to as "Kalkwasser".