Why are Beer Bottles Brown? (History & Science)

Have you ever wondered why beer bottles are brown? It is rare to find beers in clear bottles, and there is a pretty good reason behind that. We might not find those brown bottles appealing, but they serve a significant purpose. In reality, most people only recognize a beer bottle by its color, yet they cannot tell why it looks so. For that reason, we’ve decided to enlighten everyone.

While many beer bottles come in different colors, including brown, green, blue, as well as transparent colors, you might have noticed brown beer bottles are the most common. So, why are beer bottles brown? You’ll be surprised by the answer we have for you. Are you curious? Read ahead!

Why are Beer Bottles Brown (History & Science)

When did the use of brown beer bottles rise?

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Initially, brewers used glass because it was believed to be the best material to keep a liquid fresher for a considerable period of time. However, they later found out that clear glass was not the perfect choice for beer. Clear glass bottles became problematic as the beer left in the sun would quickly turn sour. The taste and smell also became unpleasant, which signaled it was time for a change.

After conducting significant research as to why beer would spoil so quickly when kept in glass bottles, Ultraviolet rays were found responsible for the damage. The rays destroyed the hop-derived acids, resulting in a skunky beer. Since we’ll be discussing this later in the article, just hold on to it a little.

Back in the 1930s, green bottles were also tradition, and people did not recognize any other color. Manufacturers even added extra chemicals to make them greener, but not until scientists discovered that the green glass caused the beer to skunk or broke down due to sunlight. Some people also had begun to notice a change of taste in the beer.

On the other hand, scientists realized that brown bottles did a better job by preventing more harmful UV rays from destroying the beer. Besides, studies have proven that riboflavin can react with alpha acids to form elements that are a bit smelly under bright conditions. If you don’t know, this reaction is what we call “skunking.” Do you now understand why most beers are in brown bottles?

As a way of preventing that chemical reaction from taking place, brown or darker glass bottles became a solution to absorb most of the light. And that’s how later on, the use of brown bottles became popular in the beer manufacturing industry.

However, due to high demand, the supply of European brown bottles went down after World War II making the brewers embark on the green glass bottles. That’s why you’ll still see the green bottled beers even today.

What are alpha acids, and how do they get into a beer

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For a better understanding, it’s time for you to learn a bit of chemistry.  Alpha acids (α-acids) are essential compounds linked with the bitterness resulting from hops used to make a beer. Hop-derived acids are weak when in a pure state and appear as pale-yellowish solids. Unrefined α-acids does not dissolve in water well and barely produce adequate bitterness. The hop can contain 2%-15% of α-acids, and it all depends on the environment in which it was stored.

If you’re not aware, hops containing a higher amount of α-acids have a greater potential of bittering a beer. When boiling the wort (a mixture of ingredients), the energy applied causes atoms within alpha acid molecules to somehow open-up. These molecules then go through an isomerization reaction to form iso iso-α-acids, which are the key contribution to beer bitterness.

What exactly is the photochemical effect of light on beer?

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Earlier, we said that brown bottles are preferably great for blocking out the sunlight, but you’re probably wondering how exactly the light destroys your beer. In other words, we call it photochemical effect of sunlight or UV lights on beers. Since a beer’s flavor is directly associated with the ingredients, it can also be affected by everything related to the brewing process.

Even after packaging and storage, the flavor of a beer continues to change dramatically, especially when exposed to light and heat. Exposing a beer to heat increases the oxidation rate of all the elements inside it, hence producing a savor or aroma that we often refer to as “cardboard,” “wet paper,” or “sherry-like.”

On the other hand, exposure of a beer to light results in very offensive aromas and flavors known as “skunk-like,” “catty,” or “lightstruck.” After storage, over a period of time, the taste of beer tends to diminish, and it may become flat. By this, we mean that the bitterness turns sweet, and you might notice a toffee-like palate when drinking your beer.

As this sweet taste continues to rise, now it’s when the beer takes on a cat-pee or catty palate. So, you can imagine how your beer will taste like for the next few weeks.  Chances of a beer being exposed to light when stored are numerous. As a matter of fact, it is possible for it to be exposed to light inside your refrigerator or while sitting on the shelf of your local beer store.

Immediately the light hits a beer; a chemical reaction occurs due to the provided energy. As a result, the iso-α-acids converts into 3-methyl but-2-ene-1-thiol (3-MBT). The “thiol” in this long chemistry name shows that there is the presence of sulfur compounds, which carry strong offensive aromas. Even a single drop of 3-MBT is enough to irreversibly spoil your beer and spread “lightstruck” odors and flavors.

Light has a detrimental effect on beer, and it becomes greater with higher energy light, which normally has a shorter wavelength. The energy produced by light with 380 nm (wavelength) is greater than the one given out by light with a 500nm wavelength.

Is the taste of brown bottled beers better?

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Well, take it from us, you will prefer the beer in a brown bottle. We are not praising these types of beers, but truth be told. Everyone wants the best flavor out of a beer, and a skunky beer is a total turn off. While both green and brown bottles help in filtering out the light, aluminum cans block it completely.

So why do we say a brown bottled beer will taste better than the one in a green or white bottle?

Since most beers are not bombarded by lasers, they are struck by visible light that is between 400-500 nanometer (nm) in wavelength and UV (Ultraviolet) light that is below 400 nanometers. Brown bottles have the ability to block light below 500 nm, while green bottles can only block out light under 400nm. Can you now relate why your occasional Carlsberg, Heineken has a pretty off taste?

White glasses gives zero, green gives 20%, and brown glass offers 98% protection against both visible and ultraviolet light. We all want the flavors in our beers to be palatable and noticeable. Losing some flavors to the photochemical effect of light degrades the powerful taste that you could experience in a beer.

To safeguard beers from possible sunlight damage, most brewers opted for a dark brown bottle to ensure that the final product reaches you uncompromised with a crispy freshness and perfect taste. Beers in brown-colored bottles are not only in good condition- crispy and fresh but also attractive to the consumer. Furthermore, you’re assured of quality standards with these types of beers.

If you have watched the corona beer advertisers, they smartly recommend you take their brew with a slice of lime. Do you think it is to add the flavor? Of course, it is to mask this off-taste with lime. Today we are here to tell you that various packaging, particularly bottle color represents how a beer should taste.

So, if you’ve been drinking a beer with flavors like those of skunk’s musky juices, it’s time for a change. If you want freshness and great flavors, brown bottles do a better job of preventing other compounds from reacting with a beer.


While beers can also be stored in green bottles, they are less affected by UV rays when packaged in brown bottles. We think the experts back in the day did a great job noticing a gap that hindered beer lovers from having the best taste out of their drinks.

The solution of opting for brown bottles is quite impressive, as the darker color blocks out the rays that completely changes the original flavors of a beer. If you’ve noticed, the reason behind why most beers are in brown bottles revolves around science with a touch of chemistry and physics.

Nobody would have thought of things like the photochemical effect of light on beer and alpha acids. But at least now you know why beers packaged in white and green bottles are not as tasty a brown bottled ones. Would you like us to clarify something? Please don’t hesitate to leave a question.

We would also like to hear from you about your experience with different beers, in white, green, and brown bottles. What would you say about their tastes?

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