How to make milk curdle? (3 ways)

In this brief guide, we are going to answer the question “How to make milk curdle?”, discuss answers to other related questions like why does milk curdle, and how do you know if milk has curdled.

How to make milk curdle?

Milk can be curdled by adding some curdling agent. Lemon juice and vinegar both work well as curdling agents. Their acidic nature hastens the curdling process. However, you also need to heat the milk to encourage the coagulation process. Otherwise, the coagulation process occurs very slowly.

3 ways to make milk curdle

Curdling dairy milk with acid

Milk can be curdled really fast by adding some acidic substance like lemon juice or lime, which will change its pH and will result in clumping of the protein part of the milk.

To curdle milk by adding some acid, warm the milk in a utensil gradually until you see steam coming out of it. Add the acidic substance like vinegar, orange juice, or lemon juice to it. For the acid choice, the most used one is lemon juice followed by vinegar and then orange juice owing to its acidity.

Stir it so that the acid can be uniformly incorporated into the whole mixture. The more acid you will add, the larger will be the particles of the curd you will obtain.

In the end, let it sit for 4 to 5 minutes and afterward strain it to separate the curd from the rest of the mixture.

Curdling dairy milk with heat

To curdle milk by heat, pour the milk into a saucepan and let it boil for 1 to 2 minutes after it reaches the boil. Meanwhile, stir the milk occasionally but do not overdo it as we want the milk proteins to clump together.

The milk will start curdling once it reaches the temperature of 180 degrees Fahrenheit or more than that.

Remove the saucepan from the heat and allow it to sit for 5 to 10 minutes. You can let it stand for even longer if you need a more curdling effect. Afterward, strain it.

Curdling soy milk

Pour the soy milk into the saucepan and heat it until the steam begins to come out of it. Now, add any acidic substance to it.

For one cup of soy milk, you have to add 1 tbsp of lemon juice. Stir it thoroughly. Then remove the saucepan from the heat and let it sit for about 10 minutes. Afterward, strain it to separate the curd from the rest of the mixture.

Other FAQs about Milk which you may be interested in.

How long is formula good for in the fridge?

Why can’t you drink a gallon of milk?

Why does milk curdle?

Milk is a complete food in itself and contains several constituents essentially fats, protein, and sugar. The most important constituent of milk, when it comes to curdling, is protein, casein. The protein in milk is typically suspended in a colloidal arrangement with the little protein particles moving around freely and randomly.

In normal conditions, these protein particles repulse one another, permitting them to roam about without clumping. But when the pH of the solution changes, nonetheless, they pul in each other and this results in the formation of the larger clumps. This is actually what happens when milk coagulates.

As the pH drops and comes out to be more acidic, the different atoms of the casein protein attract each other and become curdles drifting in the pool of clear whey. 

One thing to keep in mind about the curdling process is that it takes place more quickly at hotter temperatures than it does at cold temperatures.

How do you know if milk has curdled?

It is very easy to know if milk has curdled because:


Curdled milk develops an unpleasant, rancid odor. This odor is hard to miss and gets stronger over time.


Curdled milk tastes somewhat acidic or sour, it loses the natural sweetness of the fresh milk.


The texture and color of the milk change as well. It may begin to develop a slimy, chunky texture, and a dingy yellow color.

Can curdled milk make you sick?

Some people are very sharp at recognizing if milk has gone bad or not, but others may have no idea and drink spoiled milk. If you take a sip of spoiled milk, there will be no harm. But if you have taken up a large quantity of spoiled milk, you are at a greater risk of food poisoning.

The symptoms of food poisoning due to the intake of spoiled milk include stomach pain, nausea, vomiting, and diarrhea. You need to seek medical assistance if these symptoms worsen. Otherwise, you can be just okay after a few hours.


In this brief guide, we answered the question “How to make milk curdle?”, discussed answers to other related questions like why does milk curdle, and how do you know if milk has curdled.


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