Lye noodles are not starch. Lye noodles, also known as soda and soda ash, are edible lye. Lye noodles have a coarse texture. It is soluble in strong electrolytes and is highly soluble in boiling water. Because they are similar in color, the method of differentiation is mainly through the texture of hand rubbing.

Lye noodles are mainly used to neutralize excess acidity in traditional flour making, a process known as "making lye". It is important to use the right amount of lye, too little is called "lye small", then the noodles are dead and sour; too much is called "lye big", then the bloom and yellow color. If you use active yeast to make noodles, you basically don't need to neutralize the alkali. The alkali noodles in the boiling rice discretionary addition, can increase the viscosity, often drink on the stomach acid people have the benefit.