Caustic Potash

Brief Description:

Caustic potash is another name for potassium hydroxide (KOH).  It is the largest volume potassium chemical used for commercial, non-fertilizer purposes. (In 2005, an estimated 700,000 to 800,000 tons were produced). It is produced by the electrolysis of potassium chloride, using membrane or mercury cell technology.   KOH is a volatile solution and can be found in pure form by reacting sodium hydroxide with impure potassium to form a base of potassium hydroxide and a salt. It is a strong base and can be purchased in both liquid and dry forms.  Most frequently it caustic potash comes as a white solid that can be dissolved in less than its own weight of water.  It has universal applications in soaps and detergents, fertilizers, and industrial operations. It is also used in molten salts, dyes, pharmaceuticals, and photographic chemicals.  KOH is commonly used in the food industry due to its excellent detergent and strong antimicrobial properties.  KOH is classified as an alkaline cleaning agent, which are effective at emulsification and sapponification of fats, protein peptidization, and are efficient at removing soils, greases and oils.

Application in Wine Microbiology:

Caustic potash is used as a cleaning agent and sanitizer in wineries, mainly to clean the insides of tanks from biofilms of bacteria and yeast.  As a strongly basic inorganic compound, it works effectively to kill acidic wine organisms that are adapted to low pH environments.  It is similar to and just as effective as NaOH, or caustic soda, which is the most commonly used cleaning agent in wineries today.  KOH is considered to be more environmentally friendly than NaOH but is more expensive, making it less popular.  While it is an effective cleaner, its extremely alkaline properties make it corrosive to both people and equipment.  Skin and eye protection are necessary (or at least advised) as it can cause serious chemical burns and permanent eye damage.  It can also be corrosive to stainless steel tanks if used in overly high concentrations, and care must be taken to not misuse it.  While most commonly used in a 2% diluted form, it is also becoming popular as a base in designer winery cleaning products such as Filmaway™ alkaline cleaner from Heritage Systems.


  • Potasssium Hydroxide. (accessed 02/22/2010).
  • Potasssium Hydroxide. (accessed 02/24/2010).
  • Khan, Dr. Badruddin. Environmental Impact and Health Effects of Potassium. (accessed 02/25/20.10).
  • Heritage Systems Incorporated. (accessed 02/25/2010).