Coca-Cola is both the world’s most popular soft drink and the world’s most maligned soft drink. Its popularity has survived numerous challengers, while its notoriety remains unscathed despite the numerous hoaxes that have been debunked. New ones just keep surfacing, like this new one that claims that adding milk to Coca-Cola creates poison.
The new claim goes like this (grammatical mistakes and all) :
Take a bottle of coke…pour in a little milk, replace the lid and wait about 6 hours. when you come back, you will see it now looks like sewer water. But look at the bottom!!!! that is like gravel, sand, sludge… The coke is so acidic that when combined with the proteins in the milk, it causes a bizarre chemical reaction.
This makes me think of the root beer floats I do enjoy so much. Another thing to note is that your body is made up of proteins And imagine what it does to your body. Next time when you drink soda remember this.
Needless to say, this new claim isn’t completely true. Yes, the reaction is correct and does produce the nasty-looking concoction, but the claim is only partially correct. It is certainly misleading in its conclusion that the same thing would happen to the proteins in your body. Let’s take a look…
What Happens When You Add Milk To Coca-Cola?
Coca-Cola, like many soft drinks, use a significant amount of phosphoric acid (H3PO4) to impart an acidic taste while stifling the growth of molds and bacteria in the drink. When you add milk to Coca-Cola or any other drink with phosphoric acid, the phosphate ions from the phosphoric acid binds with the calcium molecules in the milk. Here is the chemical equation for the reaction :
3Ca + 2H3PO4 —> Ca3(PO4)2 + 3H2
The resulting compound is tricalcium phosphate (Ca3(PO4)2), which is heavy combination of two phosphate ions and three calcium ions. That’s why it sinks to the bottom. The hydrogen gas that is produced floats to the top of the clear liquid which is now (mostly) devoid of phosphate and calcium ions.
The Reaction Only Happens With Free Ions
The reaction above only happens with free calcium and phosphate ions in a solution. It doesn’t happen if you mix calcium powder with a phosphate compound.
This reaction also involves the phosphoric acid in the soft drink, and calcium ions in the milk. So the chemical reaction has NOTHING to do with proteins, as the new hoax claims. The reaction will not happen if you pour Coca-Cola over protein.
You can try that by pouring Coca-Cola over a piece of chicken… or your hand. It’s completely safe. Needless to say, the phosphoric acid in Coca-Cola and other soft drinks is not going to burn a hole in your stomach.
Is Tricalcium Phosphate Poisonous?
Tricalcium phosphate (also known as tribasic calcium phosphate) is commonly used in food preparation as an anti-caking agent or raising agent. It’s used medically as a calcium supplement, or an antacid. So it is a safe compound.
The toxic dose (LD5) is estimated to be 2 grams per kg. That means a small child with a weight of 12 kg would have to consume at least 24 grams to be in danger. An adult with a weight of 60 kg would have to consume 120 grams to be concerned about any toxicity.
We Have Been Adding Milk To Coca-Cola…
Not directly, but via ice-cream. If you have had a Coke Float, or any ice-cream float, you would have seen the reaction in your drink. You just didn’t realise it. It doesn’t make it any more or less disgusting or dangerous now that you do. 😀