Why does every beer bottle cap have 21 teeth?

Beer is a great summer beverage, and an integral part of many parties. But perhaps not everyone knows interesting information regarding serrated beer caps.

On February 2, 1892, the bottling industry was forever changed thanks to the appearance of the crown bottle cap (the type of metal beer bottle cap we often see today). This great idea belongs to William Painter , an American inventor. In his life, he had more than 80 inventions, but the introduction of the metal bottle cap was the most successful invention and quickly “turned” Painter into a rich man.

Why does every beer bottle cap have 21 teeth?
Types of bottle caps.

In the 1880s, more and more carbonated soft drinks appeared on the market and they were very popular. But the transportation of this beverage is difficult because the cork, porcelain or metal buttons do not guarantee the tightness, leading to gas loss and the quality of the beverage is significantly affected. .

Determined to prevent this phenomenon, Painter invented a bottle cap called the Crown Cork. The new bottle cap has a wavy rim and an inner liner to prevent liquid from coming into contact with the metal.

After working with bottle manufacturers to perfect the product, in 1892 Painter applied for a patent for his invention and in 1893 he founded the “Crown Cork and Seal Company”, now known as the “Crown Cork and Seal Company”. is “Crown Holdings Inc.” , the world’s leading manufacturer of corks and items in the beverage industry

As technology advances, the bottle cap is also gradually refined. The material is changed from metal to PVC, the number of serrations on the cork and the height of the cap are reduced. However, the wavy border like the crown is still retained.

Surely you will be surprised to know that Crown Holdings, Inc – Painter’s company is still in operation today. The company’s headquarters is currently located in Philadelphia, USA.

Why does every beer bottle cap have 21 teeth?
After many adjustments, the number of saw teeth was finally adjusted to 21 as it is today.

In fact, the first beer caps invented by William Painter had 24 serrations . In the 1930s, everyone used this type of bottle cap, but later they discovered that because there were too many serrations, the beer bottle cap was too tight and difficult to open.

After many repeated experiments, the number of sawtooth was finally adjusted to 21 as it is today. But why 21 cogs?

Due to the best performance in tightness, rigidity and ease of opening, the 21 serrated beer cap has been perfected and become the international standard.