Here's What Those Yellow Caps On Coca-Cola Bottles Really Mean

When you consume a product frequently, small changes in the exterior packaging can be very noticeable when you see them. Thus, the yellow-capped bottles of Coca-Cola stick out like a sore thumb when you see them arrive in stores each spring. While a glass bottle of the beloved soda typically leads one to believe it's Mexican Coke — the superior version of the cola — a yellow cap means that the drink is made solely from ingredients that are Kosher for Passover, a holiday that is observed by Jewish people each and every year in either March or April.

While standard Coke is generally considered a Kosher soda — and has been since 1935 when it became certified Kosher — that is only technically the case for the majority of the year. Those who follow the Kosher dietary restrictions are allowed to drink Coke products year-round, but Passover itself enforces even harsher restrictions for the eight days the holiday is observed. Thus, while the standard bottles of Coke are typically Kosher, they no longer are throughout Passover, necessitating the yellow-capped bottles.

Now, while Coca-Cola's formula is famously a well-kept secret, there are certain ingredients that are well-known to the public, including the one that is not deemed Kosher during Passover each year. That ingredient is high-fructose corn syrup, which is not allowed to be consumed during the 8-day holiday due to the fact that it contains Kitniyot, a Hebrew word that means legumes, rice, and corn, something that Ashkenazi Jews specifically are not allowed to have. 

Furthermore, high-fructose corn syrup can sometimes be produced with — or, at the very least, contaminated by — leavened grains like barley, rye, oats, and wheat, which are considered chametz and are off limits for all observers of the Passover holiday. So, instead of high-fructose corn syrup, each Coke product with a yellow cap is made with sugar in its place. 

Even if you aren't observing the Passover holiday, the product could better fit your tastes anyway. Though, far warning: When it comes to sugar or high-fructose corn syrup, too much of either can be very bad for your health.