Question

A child wonders as to why her mother touches the warm milk with her finger before adding a little curd to for setting curd. Explain.

Answer 1

Hint: Curd is a fermented milk product whose origin is from the Indian subcontinent. It is a natural probiotic and is also referred to as dahi, doi, Perugia. It is usually prepared from cow's milk, and at times from buffalo milk or goat milk.

Complete answer:
Curd is prepared by bacterial fermentation of milk in which lactose is converted into lactic acid by several probiotic microorganisms. The species which are involved in the fermentation process depend on the temperature and humidity of the environment. They may comprise of Lactococcus lactis, Streptococcus diacetylactis, Streptococcus cremoris, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus.

A child wonders as to why her mother touches the warm milk with her finger before adding a little curd to for setting curd. This is because, as the pH drops and becomes more acidic, the protein molecules attract one another and become "curdles" floating in a solution of translucent whey. This slogging response occurs more swiftly at warmer temperatures than at cold temperatures. So the mother checks the temperature of the milk before adding curd to it because curd and temperature both are accountable for increasing the acidity of milk and curdling of milk.

For best outcomes, one can add 3% skim milk powder. Premixing 3% good curd in milk, adding to the rest and then keeping at 40-45°C, wrapped with cloth to prevent cooling. Put it in the fridge when it's a little sour. Avoid harmful bitter tastes and don't reuse bitter curd. This method can also be applied for making curd from milk substitutes, for example, soy milk.

Note: Curd products differ by region and include different types of cheese. In England, curds manufactured using rennet are referred to as junket. Cheese curds, soaked in the whey and served without further processing, are prominent in some French-speaking nations. These are often sold in snack-sized packaging and seen as a typically Canadian food item. In Wisconsin, curds are eaten fresh without additional, or they are breaded and fried. In Mexico, chongos zamoranos is a dessert made with milk curdled with sugar and cinnamon.