In fact, these two types of alkaline water are not the same. Many people use them interchangeably if they have different chemical properties, but the effects are different.

The alkaline water in German alkaline bread refers to: sodium hydroxide, the chemical formula is NaOH, commonly known as caustic soda, fire soda, and caustic soda. It is a highly corrosive alkali, usually in the form of flakes Or in block form, it is easily soluble in water (it releases heat when dissolved in water) and forms an alkaline solution. It is also deliquescent and can easily absorb water vapor (deliquescence) and carbon dioxide (deterioration) in the air. Hydrochloric acid can be added to check whether it has deteriorated. .

Mooncake alkaline water is ordinary edible alkali dissolved in water. :

It refers to soda ash (sodium carbonate) (chemical formula Na2CO3) and baking soda (sodium bicarbonate) (chemical formula NaHCO3) that are different from industrial alkali. Baking soda absorbs carbon dioxide from a solution or crystal of soda ash. There is no fundamental difference between the two finished products. Therefore, edible alkali is also called baking soda (powdered) in some places. Edible alkali is in solid state, round, white in color, and easily soluble in water.