E501: Potassium carbonates

What is E501?

Potassium carbonates are alkaline potassium salts. E501 covers potassium carbonate and potassium hydrogen carbonate (potassium bicarbonate), both white, water-soluble powders.

Origin and production

They are produced industrially from potassium hydroxide, which is made from potassium chloride, by reacting it with carbon dioxide. Historically potassium carbonate was obtained from wood ashes, known as potash.

Why is it used?

Potassium carbonate raises the pH of foods. It is a component of 'kansui', the alkaline water that gives ramen and other instant noodles their springy texture and yellowish colour, and it is used to alkalise ('Dutch process') cocoa powder for a darker colour and milder flavour. It can also act as a raising agent in some biscuits.

Vegan, vegetarian and halal

Potassium carbonates are mineral-derived and suitable for vegans and vegetarians. They are not generally a halal or kosher concern.

Safety and regulation

Potassium carbonates are authorised as food additives in the EU and may be used at the level needed for their purpose.

Common in