E501ii - Potassium hydrogen carbonate
What it is and how it is used
Potassium hydrogen carbonate is the potassium twin of bicarbonate of soda — the same chemistry with potassium in place of sodium. It is made by passing carbon dioxide through a potassium carbonate solution.
The swap matters for one reason: it raises dough without adding sodium. That makes it the raising agent of choice in reduced-salt and “no added sodium” bakery products, where a conventional bicarbonate would undo the salt reduction the recipe is built around. It also serves as an acidity regulator, notably in winemaking, where it is used to soften excessive acidity in the must.
Foods commonly containing it
Reduced-sodium baking powders and bakery products, some wines (as a de-acidifying agent), effervescent supplement tablets, and sparkling and mineral drinks.
Safety summary
Potassium carbonates are authorised in Great Britain as E 501 and sit in Group I, permitted at quantum satis. Potassium hydrogen carbonate is specified as E 501(ii).
No numerical ADI has been assigned. Potassium and carbonate are ordinary dietary constituents.
One qualification worth stating: people with reduced kidney function, or taking potassium-sparing diuretics or ACE inhibitors, are usually advised to watch total potassium intake. Read more on potassium.