GDL is a multifunctional ingredient that can be used as a coagulant in tofu, a leavening acid in the bakery (e.g. bread, cakes & pastries), controlled release acidulant & curing accelerator in processed meat & seafood, mild acidulant, chelating agent, and buffering agent in food.

Coagulant in Tofu
Glucono delta-lactone can be used as a coagulant in tofu for its gradual acidification initiates the curdling of the protein. It can replace the function of nigari or in combination uses with nigari in tofu. The following steps are how to make silken tofu with GDL.

Step 1: Select beans

It is recommended to pick light white soybeans with good color and high protein content.


Step 2: Soaking beans

The time and temperature of soaking beans should be appropriate. Beans are easy to ferment and protein is easy to lose if soaking time is too long. The quality & yield of tofu will be decreased if with a short soaking time, along with less soy milk.

Quantity: for example, soak 500 g of dry soybeans to obtain 1000 g – 1100 g of wet soybeans.

Temperature and time: Soak 6 – 7 hours at 15 °C,  or 5 hours at 20 °C, and 10 hours or more if in winter.

Water & PH: it is better to use soft water, such as surface water or tap water to soak beans. It is also recommended to add baking soda, about one-thousandth of the weight of the bean to adjust the pH value of the water to promote protein leach. The amount of water used should make sure to submerge soybeans completely.


Step 3: Refining

It can be used with stone grinding or refining machine. It is required to grind the wet beans twice and adding water while grinding. 1500 grams added at the first refining, and 750 g for the second refining.

Step 4: Discharge Air Out

Put 20-30 grams of edible oil in the heated pot until the oil is boiling, then add a small amount of warm water (about 50 °C), and pour into the soy milk and stir for 5 minutes.

This step is mainly to discharge the air out of the soy milk and reduce the viscosity to make sure soy milk can filter quickly and filter thoroughly.


Step 5: Filter

Cloth or gauze can be used as a filter to separate the soy dregs and soy milk. 60°C water is used several times, and stir the filter residue while adding water. Totally, around 1750 grams of water is used in this process and finally get the pure soy milk.

This step is to filter soy dregs and get soy milk or obtain protein completely.

Step 6: Cooking

Cooking pure soy milk with a fierce fire.


Step 7: Making Tofu

There are two ways to make soft tofu, Cold process or thermal process.

Cold process: cool the soy milk down below 30 °C, then add 9 (can be less if with nigari) grams of GDL and stir it. Then put soy milk in a smooth box or in a food bag, steam it for 25 minutes or directly place the box or bag in boiling water for 25 minutes and wait it cools to form tofu.

Thermal process: cool the soy milk down to 90 °C, then put GDL and stir it. Soon put soy milk into the box for 15 minutes.