On October 14, 2026, there are various unconventional drink combinations on the market that continue to innovate. Beverages such as cola, soda, and milk from cows are fundamentally different, but some businesses have combined them to create uniquely flavored products. So, what would happen if you were to mix carbonated drinks with milk?
A popular Instagram account called “thedadlab” often shares science experiment videos for children to satisfy their curiosity and thirst for knowledge, amassing over 1.11 million followers to date.
In one of his shared videos, he poured milk into bottles of carbonated drinks and observed the subsequent changes. The selected carbonated drinks were from the Coca-Cola Company, including Coca-Cola, Fanta, and Sprite.
After adding milk for 30 minutes, the milk congealed in the carbonated drinks could be observed. Within 24 hours, all congealed milk sank to the bottom of the bottle, forming colored solid chunks. Each beverage exhibited a similar reaction, albeit with varying shades.
“thedadlab” explained that phosphoric acid or citric acid in these drinks can cause proteins in milk to coagulate instantly. The acid molecules bind with calcium, forming dense clumps that sink to the bottom, taking away some color as well.
The pH values of Coca-Cola, Sprite, and Fanta range from 2.5 to 3.5, while milk has a pH value of 6.7. This acidity is sufficient to trigger milk coagulation upon contact. This process is similar to what happens when milk interacts with stomach acid after consumption, albeit unseen.
According to Food Republic, the curdling of milk is a common occurrence. For example, adding cream to acidic soups, squeezing lemon juice into milk, or when milk turns sour can result in similar situations.
When milk sours, bacteria consume its natural sugars, producing lactic acid, increasing acidity, leading to protein coagulation. This reaction also occurs when milk is mixed with carbonated drinks.
Although people don’t typically mix carbonated drinks directly with milk in daily life, milk does find its way into carbonated drinks in various forms. One famous example is the “Dirty Soda” in Utah, USA.
However, heavy cream, half-and-half, or full-fat coffee creamers are often used instead of regular whole milk. These dairy products with higher fat content provide a smoother texture, stability, and prevent separation in the mixed drink.
In various U.S. states, different milk and carbonated drink blends exist, such as “Pilk,” a concoction of Pepsi and milk, found in the popular “Dirty Soda.”
In a Pepsi commercial from 2022 featuring American actress and singer Lindsay Lohan drinking Pilk, this combination gained popularity, sparking a viral trend on the internet.
Similar drink combinations exist worldwide. For example, in Pakistan, there is a beverage called “doodh soda,” made by mixing Sprite or 7Up with cold milk and sugar, often consumed during breaking fast in Ramadan.
Due to the tendency of milk curdling or separation in such drinks, they are often homemade following traditional methods rather than being available on store shelves.