Why Some Coca-Cola Bottles Have Yellow Caps At The Grocery Store

If you see a Coca-Cola bottle with a new-to-you yellow cap, no, the iconic brand is not changing its historic colors. The cap color, which is often stamped with O-U-P, is to help Jewish shoppers identify which products are certified kosher during Passover – a commemoration of the Israelites' pilgrimage from slavery to freedom as described in the Hebrew scriptures. During the observance, Jewish people aren't supposed to eat leavened foods or items made with barley, oats, wheat, rye, or spelt. Essentially, observers practice a gluten-free diet for the celebration while following the dictates spelled out in Exodus 12:14-15.

Although Coca-Cola has the certified kosher stamp on the product, its high-fructose corn syrup doesn't meet the Passover standard. Yet, while standard-issue Coke is no longer considered to be one of the surprising Passover-friendly foods, this wasn't always the case. Prior to 1980, the company made its soda with sucrose (sugar derived from beets or sugar cane). But it's not just the formula change that makes standard Coca-Cola off-limits during Passover. The recipe also uses an enzyme (alpha-amylase) crafted from barley that's similarly a no-go for anyone observing the occasion.

The limited edition yellow caps didn't first appear during the '80s. The Coca-Cola company has been implementing the lids since 1935. This happened after Rabbi Tobias Geffen met with Coca-Cola executives to analyze the formula. Geffen's analysis determined that the popular soda wasn't kosher. The rabbi identified two substances – glycerin (a byproduct from making soap) and fats derived from pigs and cattle not slaughtered using kosher rules — that needed to be substituted to make the soft drink kosher. Coca-Cola made the change in time for Passover. The new caps were only available in Atlanta and included a rabbinical product certification (known as a hekhsher).

Today, the yellow caps appear in grocery stores around the United States, and especially in locations that may have a significant number of Jewish people. However, they aren't the only ones looking for the limited Coca-Cola. Fans of the unique taste of Mexican Coke also flock to the yellow caps, claiming that the soda tastes cleaner than the high-fructose version.