Why are glass beer bottles green or brown?

This starts from the mid-nineteenth century, when the glassmaking process was immature. Impurities in glass raw materials cannot be eliminated by [ferrous ions], and the glass wine bottle is more or less green. In fact, it is not just beer bottles. In the era when glass technology was underdeveloped, glass windows and ink bottles were all green. Then glass technology developed later, why are beer bottles still green? This is because everyone has found that beer will oxidize and taste bad after being exposed to sunlight, and the shelf life is longer if it is packed in a green glass bottle! There are brown glass bottles that can also extend the shelf life. And it works even better! So then there were some, brown glass bottles of beer. Green and brown glass bottles are by far the mainstream for beer bottling.

Later, with the development of the glass industry and the popularization of refrigerators, fresh-keeping and sealing technologies were no longer a problem. The color of the beer bottle will not have much impact on the shelf life. So there are beer bottles of various colors.

But many classic breweries with good reputation still use green glass bottles. Also deliberately add some green to the beer bottle. Make it green more evenly. Gradually, beer bottled in green glass has become one of the classic signs of “good beer”.