The name Jiāng zhī zhuàng nai 姜汁撞奶 translates to “ginger juice crashing into milk”, alluding to the cooking process: ginger and milk proteins react at 158°F condensing to form a solid curd.
Ginger contains rennet, which chemically reacts with milk proteins.
A protein in milk transitions from a soluble to an insoluble state, causing the milk to coagulate.
It is a dessert originating from Guangdong, in the southern province of China. And it is undoubtedly one of the most famous desserts in Hong Kong.
It would be better to use water buffalo milk, because it is denser, easier to coagulate.
The ratio of ginger juice to milk should be about 1:10.
This dessert resembles another Chinese dessert:
- Difficulty: Medium
- Cost: Very cheap
- Rest time: 20 Minutes
- Preparation time: 5 Minutes
- Portions: 1 Person
- Cooking methods: Boiling
- Cuisine: Chinese
- Seasonality: All seasons
Ingredients
- 1 cup water buffalo milk
- 1 teaspoon sugar
- 0.4 inch fresh ginger (preferably old)
Tools
- 1 thermometer
Steps
Bring the milk to a temperature of 158°F.
Peel and squeeze the ginger, extracting the juice.
Pour the juice into the milk and wait about 20 minutes for coagulation.
FAQ (Questions and Answers)
What is the biochemical principle that creates ginger curd?
The most important part of ginger in ginger milk curd is ginger protease: zingipain.
This substance with a molecular weight of 31 kDa is found in three forms with isoelectric point values around 5.58, 5.40, and 5.22, respectively.
The three forms have very similar biochemical behavior, where the optimal proteolytic activity is 104–140 °F and maximum coagulation activity at 158 °F. [5]
Milk is a substance mainly composed of milk fat globules and casein micelles in a continuous phase of water, sugar, whey proteins, and minerals.
Casein micelles are mainly composed of α(s1)-casein, α(s2)-casein, β-casein, and κ-casein, where the hydrophobic α and β-casein are located in the internal submicelle and the hydrophilic κ-casein is found on the outside.
When the milk begins to curdle, the curd is small, but as coagulation progresses, the size of the curd increases until the milk ends up with a tofu-like structure.
When curdling occurs, ginger protease cuts κ-casein so that the hydrophilic C-terminal and hydrophobic N-terminal separate. This disrupts the stability of the casein micelle.
