Why does soy milk curdle in coffee?

In this brief guide, we are going to answer the question “why does soy milk curdle in coffee” with an in-depth analysis of the possible reasons behind soy milk curdling. Moreover, we are going to discuss the nutritional profile of soy milk and the ways by which you can keep soy milk from curdling in your coffee. 

If it ever happened to you that you are all set to make yourself a delicious cup of soy milk coffee but as soon as you add soy milk to your coffee it clumps together and settles down? Yeah! We all have been there so if you are wondering “Why does soy milk curdle” then you need not worry as we are here to tell you everything about soy milk curdling.

So without much ado, let’s dive in and figure out more about it.

Why does soy milk curdle in coffee?

There are two factors, temperature, and acidity, that are chiefly responsible for the curdling of soy milk.

Acidity

Acidity is the main reason behind the soy milk curdling. As we all know that ground coffee, instant coffee, or black coffee is more acidic than soy milk itself. Being more acidic means that the pH of the coffee is lower as compared to that of the soy milk. 

Soy milk has a curdle point of 5.5 while the pH of the coffee is 5. So when high acidic coffee comes in contact with the basic soy milk, it makes the soy milk curdle. It coagulates the soy milk and the clumps soy milk settles on the base of your cup, leaving you with a cup of coffee that is just a disappointment.

Temperature

Heat accelerates the process of curdling soy milk. The hotter the temperature is the more are chances for soy milk to curdle. So when it comes to coffee, heat combined with the high acidity of the coffee serves as the icing on the cake and totally curdles your soy milk.

What is the nutritional profile of soy milk?

One cup of soy milk has 80-100 calories in it. It is a good source of protein and has about 7 grams of protein, 4 grams of fat, and 4 grams of carbohydrates. It is a good source of potassium and comes fortified with calcium, vitamin D, and vitamin B12. It has a very low amount of saturated fat present in it and does not contain cholesterol that makes it an odd low-calorie milk substitute.

What do you mean by curdling?

Curdling is basically the formation of large clumps which are formed when the colloids or the emulsions break down.

Soy milk has about 7 grams of protein content per cup and it is the protein that plays the most important role when it comes to curdling. The protein in soy 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 drops and becomes more acidic, they pull in each other and this results in the formation of larger clumps. This is actually what happens when soy milk coagulates. 

What happens when you drink curdled soy milk coffee?

As long as the coffee grounds and the soy milk that you used to make the coffee were fresh, you can drink the curdled soy milk coffee because the reason for the soy milk to curdle in this scenario was the high acidity of the coffee that ultimately changed its pH and resulted in soy milk clumping and curdling. One thing to keep in mind is that it won’t have that great taste or mouth feel to it but it also won’t cause health issues even if you consume it.  

How can you keep soy milk from curdling in your coffee?

  1. You can try warming the soy milk a bit (but not more than 60ºC) and adding it to the cup first. Afterward, slowly pour your coffee, and voila! You have your soy milk coffee.
  2. You can also keep soy milk from curdling in your coffee by letting your coffee cool up a bit before adding soy milk to it. Adding the soy milk in hot boiling coffee will result in instant curdling of soy milk so you should look out for that.
  3. Going for low-acid coffee will also keep soy milk from curdling in your coffee.
  4. You can even try experimenting with using soy milk from different brands and once you find your perfect match that does not curdle in coffee, all you gotta do is to just stick with it.
  5. You can also try to warm and froth the milk separately and afterward adding coffee to it.

Conclusion

In this brief guide, we answered the question “why does soy milk curdle” with an in-depth analysis of the possible reasons behind soy milk curdling. Moreover, we discussed the nutritional profile of soy milk and the ways by which you can keep soy milk from curdling in your coffee. 

Citations

https://www.thekitchn.com/why-does-soymilk-curdle-in-hot-148329

https://www.buzzfeed.com/ailbhemalone/this-is-how-to-stop-soy-milk-going-weird-in-your-coffee

Avatar

Mahnoor Asghar is a Clinical Nutritionist with a bachelor's degree in Nutrition and Dietetics. She is compassionate and dedicated to playing her part in the well-being of the masses. She wants to play a fruitful role in creating nutrition and health-related awareness among the general public. Additionally, she has a keen eye for detail and loves to create content related to food, nutrition, health, and wellness.

Leave a Reply

Your email address will not be published. Required fields are marked *