Also referred to as potash or pearl ash. It is a milder alkali than potassium hydroxide with a pH of 11.6. It is not strong enough to completely saponify oils into soap and glycerin but it does react with free fatty acids in your formulas to bind them up into soap which adds to the transparency and shelf life of your liquid soap. Most commonly used in no paste liquid soap recipes. Always add potassium carbonate at room temperature or lower to avoid volcanos.