The beer now is not produced in colorless glass bottles but in fact, in the past it was kept in transparent glass containers.
The old Egyptians, also made beer. It started bottling in the 19th century, when parallel with the commercialization of the drink, the brewers established that in that case it remains fresh for longer time.
As mentioned, they initially sold the beer in colorless glass bottles, and it worked great until the beer was kept in cold and dark rooms.
However, the brewers soon realized that when the beer is exposed to the sun, it receive unpleasant smell almost “like a skunk.”
To such an unpleasant smell is coming because the aqua glass passes the UV rays and penetrate into the drink and alter its taste, liberating the acid from hops.
The acid then comes in reaction with the sulfur present in the beer and produces a compound very similar to what the skunks are releasing when they defend themselves from predators.
So, the manufacturers of beer put in use the brown glass bottles, whose dark color prevents from unwanted penetration of ultra-violet rays, so the beer inside stays fresh for long time.
During World War II, along with a lack of supplies, the green bottles began to appear too. Produced beers were still made primarily in brown bottles, but though rarely, it had it in green.
After some time rumors and urban myths began to circulate in an attempt to explain the emergence of green bottles and listening to this kind of speculations, more and more people were deciding to drink beer only in green glass, which contributed to the growth and the popularity of the same.
It was all happening until a technologist of a certain brewery did explain that the assembly line in his factory, placed every 99 or 999 brown bottles in a green, exclusively for monitoring the production volume and sampling for quality assurance.
Meanwhile, it has developed a technology which protects the aqua glass from UV rays, but manufacturers remain faithful to the tradition.
Sounds logical to us, that this is so, because the dark glass is a cheaper alternative rather than the glass with UV protection.