Lye Water

How to make homemade lye water for use in recipes such as Pretzels and Mooncakes. Recipe with step-by-step photos.

What is Lye Water?

Lye water is a food-grade alkaline water used in some recipes to help with texture or colour.

For example, lye water gives Pretzels their signature dark brown colour and taste. For Mooncakes, a small amount of lye water is used to give the dough a deep, golden colour.

Where to Buy Lye Water

Lye water is readily available in Asian grocery stores in some countries, but not in others. It is often labelled as “Kansui” on most Asian packaging, and it is essentially a clear solution which contains potassium carbonate.

Due to its potency and irritant factor, lye water is banned in some countries. At certain concentrations, lye water can irritate the skin, which is why it is not readily available everywhere, and why lye is often sold with strict instructions for safe handling.

Homemade Lye Water

A good substitute for lye water is a simple homemade lye water.

You can make your own lye water at home with just baking soda and water. Baking soda is an alkaline substance, and baking the baking soda intensifies its alkaline properties.

So a solution containing baked baking soda will be more alkaline than just using normal baking soda.

Recipe for Lye Water

To make the lye water for use in most recipes (such as for Mooncakes), use a ratio of 1:4 (1 part baked baking soda : 4 parts water).

So if a recipe requires 1 teaspoon of lye water, simply mix 1/4 teaspoon of baked baking soda with 1 teaspoon of tap water.

Other recipes might specify what concentration of lye water is required. For example, when making my Soft Pretzels, I use a ratio of 1:2.

How to Make Lye Water

Step 1

Spoon the baking soda into an oven-proof dish, preferably large enough so that the baking soda can be spread out in a thin layer.

Bake for 1 hour at 120°C/250°F (without fan).

Step 2

Let the baking soda cool completely before transferring it to an air-tight container for storage, and label it accordingly. I like to use a glass spice jar.

Step 3

Make the lye water just before you need to use it. Simply dissolve the baked baking soda in some cold water.

Precautions When Making Lye Water

Food-grade lye water is fairly mild and is safe for cooking. However, people can react differently when their skin comes into contact with lye water.

Hence, to be on the safe side, avoid touching the baked baking soda with your bare hands, and wear gloves if you are a bit clumsy in the kitchen.

Recipes Using Lye Water

The following recipes use Lye Water:

Mooncakes with Lotus Seed Paste and Salted Egg Yolk

Soft Pretzels

Print