Potassium bicarbonate, also known as baking soda, is a natural mineral that can be used to reduce acidity in wine. It is a safe and effective product that is widely used by winemakers.
 
Potassium bicarbonate works by reacting with tartaric acid, the primary acid found in grapes, to form potassium tartrate. Potassium tartrate is a more soluble precipitate than calcium tartrate, which means that it will not settle to the bottom of the wine as quickly. This makes potassium bicarbonate a good choice for acid reduction in wines that need to be bottled quickly.
 
Potassium bicarbonate can also be used to improve the mouthfeel of wine. It can help to soften harsh tannins and make the wine more smooth and round.