Cantonese snack ginger hit the milk, why does the milk on the ginger juice "bump" solidify?

Ginger bump milk is a famous snack in Guangdong Province, and there is a legend about it. Once upon a time, in Shawan Town, Panyu, Guangdong Province, an elderly old woman had a cough disease, and heard that ginger juice can treat cough, but ginger juice was too spicy for the old woman to drink, so the daughter-in-law poured milk into a bowl filled with ginger juice. As a result, after a while, the milk actually solidified. The old woman dug up with a spoon and took a bite, the entrance was lubricated like a tofu flower, and she felt full of fragrance. Since then, ginger bumping milk has spread in Shawan Town.

Although it is a legend, there is also a scientific truth in it. With the development of science, it has been found that 95% of the casein in cow milk exists in the form of gum particles, which are about 40 to 300 nm in diameter. The casein in milk is charged negatively on the surface of the liquid, and the casein molecules repel the same charge, so when the milk exists alone, the casein molecules exist alone, in the form of an emulsion.

The reason why buffalo milk coagulates after encountering ginger juice is because after the ginger protease is hydrolyzed under certain conditions, the charge of the casein gel is neutralized, so that the milk coagulates into a colloid. In this process, a charge neutralization occurs, the substance is still the original protein, and no new substance is generated, just a physical change!

Regarding ginger bumping milk, there are many theories circulating on the Internet, the old theory is that ginger contains proteases, and chemically reacts with the proteins of milk species, so that this protein changes from a soluble state to an insoluble state, so the milk coagulates. This theory has proven false.

So, is this also the truth of the production of yogurt? Yogurt is the introduction of lactic acid bacteria into the milk, using a constant temperature fermentation method, in which lactose produces lactic acid, lactic acid denatured the casein in the milk, so that the whole milk appears curdled. Unlike ginger, the lactic acid bacteria in milk break down lactose to form lactic acid, turning milk into yogurt. In this process, new substances are generated, so it is a chemical change.

What is the trick to making ginger and milk? The milk should not be too hot or too cold, rinse into a bowl at about 70 ° C, and then do not stir until it solidifies.

In addition, a key trick is that the milk must be water milk. The price of buffalo milk is 2 to 3 times that of black and white flower milk, and the nutritional value is 4 to 5 times that of flower milk. According to expert tests, the zinc content of buffalo milk is 12 times that of flower milk, the calcium content is 1.29 times, the total dry matter content is 50% higher than that of flower milk, and the milk fat rate is 1 times higher. Moreover, buffalo milk looks whiter, thicker, and more fragrant and sweet to drink.

Do you understand ginger bump milk and yogurt? After understanding the principle, can you use papaya juice to make papaya to hit milk, and pineapple juice to make pineapple to hit milk? Go home and give it a try.