Alkaline and lye are the same thing because the ingredients are the same.

Alkaline water is a common traditional ingredient in Cantonese pastries. It is an alkaline solution obtained by our ancestors by boiling grass ash with water for one day and taking the supernatant, which has a pH value of 12.6. The main components of grass ash are potassium carbonate and sodium carbonate. In the absence of modern chemical alkali in history, we have to use this kind of plant alkali prepared by local method.

The alkaline water used now is no longer grass ash, but according to the composition and principles of grass ash, potassium carbonate and sodium carbonate as the main ingredient, supplemented by carbonate or polymerized phosphate, formulated alkaline mixtures, functionally the same as the grass ash alkaline water, so it is still called alkaline water. If only potassium carbonate and sodium carbonate are used to formulate the alkaline water, it is very unstable in nature and is prone to failure and deterioration when stored for a long period of time. Generally, 10% of phosphate or polymerized phosphate is added to improve water retention, viscoelasticity, acid and alkali buffer and metal blocking power.

Alkaline water is mainly used in baking, alkaline water, alkaline water and inkstone water, are known as composite additives, now generally do not use, the Baking Association suggests that the use of potassium carbonate 15%, 5% sodium carbonate, mineral water 80% of their own preparations, to be written on the label, "Food Additives: Potassium Carbonate, Sodium Carbonate.