In this brief guide, we will answer the question “How to add lemon juice to milk without curdling?”, discuss how to prevent milk from curdling while cooking, and can curdled milk make you sick.
How to add lemon juice to milk without curdling?
There are two ways to add lemon juice to milk without curdling:
- Raise the pH of lemon juice
Before adding lemon juice to the milk, raise the pH of lemon juice. Milk curdles at pH 4.6, so add baking soda to the lemon juice to bring its pH near neutral before adding the juice to the milk.
- Add lemon to the cold milk
When you add lemon juice to the milk, the temperature is the key player to decide if it will curdle or not. If you add lemon juice to the milk when it is hot, it will curdle immediately. Therefore, try to add lemon juice to the milk when it is cold so that it does not curdle immediately.
Why lemon makes milk curdle?
Milk is composed of several molecules, primarily fat, protein, and sugar. The most important protein that makes milk curdle is casein protein. The molecules of casein float independently and repel each other, as milk is a colloidal solution, without clumping.
When you add lemon juice to the milk, its pH drop due to increased acidity, and the protein molecules suddenly attract each other to form clumps and become curdles floating in a solution of translucent whey. This reaction of clumping happens more swiftly at a warmer temperature.
How to prevent milk from curdling while cooking?
For your sauce or soup, you will not want curdled milk. Instead, you will want to have smooth and nice milk. So, to prevent milk from curdling when you heat it, follow these tips:
- Do not let the milk boil
To prevent the milk from curdling, heat the milk gently over medium-low heat. Because if you heat it too quickly, even if it never comes to a boil, it can still curdle milk. Avoid boiling because it is a sure way to curdle milk.
- Stabilize milk with starch
Try to thicken your sauce or soup with roux before adding milk to prevent the milk from separating. You can also add starch (such as flour or cornstarch) to help stabilize the milk emulsion. This changes the makeup of the liquid and prevents curdling.
- Avoid strong acids
Avoid the addition of strong acids such as vinegar, wine, tomatoes, or lemon juice along with the milk, because in such case, the milk will be more likely to curdle. If you still want to add, use a starch along with the acid to overcome the effect of acid.
- Season at the end
Salt is an important ingredient to season your soup. But it can cause the milk to curdle. The tip to follow here to avoid milk to curdle is to add salt at the end of your recipe.
- Temper the milk
Adding cold milk to the hot liquid content of the soup can cause it to curdle. So, to add milk to the soup, temper the milk first. For this, take some hot liquid in a bowl and add milk to it. Whisk it until it gets hot enough and then add this to the soup.
How to know if milk has curdled?
It is very easy to know if the 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 fresh milk.
The texture and color of the milk changes 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 to recognize if the 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 may include stomach pain, nausea, vomiting, and diarrhea.
Can you use curdled milk?
Though you should not drink spoiled milk. But if it is just a little off and slightly acidic there are several ways to use it:
- You can make biscuits, pancakes, scones, and cornbread by using curdled milk. Just substitute the fresh milk, buttermilk, or yogurt in the recipe with the curdled milk.
- A splash of spoiled milk can help thicken and add richness to soups and stews.
- You can use sour milk to make creamy dressings like ranch, caesar, or blue cheese.
- You can also use sour milk to make homemade cottage or farmer’s cheese.
In this brief guide, we answered the question “How to add lemon juice to milk without curdling?”, discussed how to prevent milk from curdling while cooking, and can curdled milk make you sick.