Why are beer bottles opaque? That's because the most important thing to keep beer fresh is hops, but in the sun's ultraviolet radiation, beer hops will break down, producing a slightly smelly "sunshine smell."
Colored glass can reduce this reaction to a certain extent, and the effect of brown bottles is better than that of green bottles. If there is a clear bottle of beer in the market, its hops are specially treated.
Why are PET beer bottles opaque? Another reason is that beer will rapidly sublimate after heating, decomposition into carbon dioxide, if it is a transparent bottle, sufficient sunlight, it will produce a large amount of carbon dioxide in a short time, the easy beer bottle is certain, in more and more carbon dioxide generation at the same time, it is likely to explode phenomenon, will cause dangerous accidents. Therefore, PET transparent plastic bottles can not contain beer!