What causes milk to curdle?

Answer 1

One thing is citric acid, which is why you have to be careful with hot tea. You squeeze in a little lemon after you pour in the milk and WHAMMO, instant junk

Answer 2

Given the right circumstances, any milk or cream product will curdle (a process in which the curd protein, casein, coagulates and forms clumps). Acid, heat, and salt are the antagonists, all of which cause curdling. The milk has only one defense mechanism, which you don't want to hear about — fat. The more fat it contains (and the fresher it is), the less likely it is to curdle. There is a dramatic difference in the ability of heavy cream vs. light cream to resist curdling. To bring skim milk into the equation is almost asking it to curdle.

Answer 3

iron.









Haven't you heard of a curdling iron?



:P

anyway:

Best Answer - Chosen By Voters

There are a few causes for this. It can either be chemical or biological. Heat can also cause this. Milk curdle because its protein coagulates and becomes a solid mass. This is the same with boiling an egg. Acids and certain microorganisms can also do this given the right conditions.

Answer 4

Separation of the milk solids from the whey. If you are referring to when milk goes bad, its because you get a build up of bacteria (such as lactobacilli) that make the milk a bit acidic. The acid will split the milk, in the same way adding vinegar to milk will make it curdle.

Answer 5

When milk is pasteurized, the flash of heat kills the pathogens but not the bacteria commonly found in milk.

The bacteria that remain use the lactose sugar in the milk for food, and in the process they produce an acid that coagulates the proteins.

The higher the fat content, the lower the microbe count (usually) since most bacteria can't survive in fats or waxes.

Answer 6

A chemical reaction.The increased acidity causes the milk proteins (casein) to tangle into solid masses, or "curds".Thats why milk curdles!

Answer 7

its not acidity, its bacteria in the air in the container which turns it sour

Answer 8

aging... but dont worry when its done you got cottage cheese!!!

Answer 9

vinegar

Answer 10

acid