Why Is Tea Brown? Answered

“Why is tea brown?” is one of the most common questions you may come across when steeping different types of tea. Let’s find out more in this comprehensive guide.

Why is tea brown?
Having low-quality tea is one of the reasons why tea turns brown

Have you ever wondered, “why is tea brown?” There are four reasons why tea turns brown when it comes in contact with water. Having low-quality tea is one of the reasons, but dig in deeper, and you will see that exposure to sunlight, oxidation, and poor brewing technique also leads to an unpleasantly dark brown color while the tea is supposed to be green.

Some certain varieties of tea are supposed to brew a beautiful amber color when steeped, such as black tea, Assam, Ceylon, and Pu-erh. Let’s dig in.

4 Reasons Why Is Tea Brown?

1. Oxidation

The most common factor leading to the change of color in tea when brewed is the oxidation process. When the tea leaves come in contact with oxygen in the air, the enzymes in the tea turn brown and break down over time.

Most of the time, oxidation happens as soon as the leaves are plucked from the tree. Crushing and rolling the leaves also enhances the oxidation process. 

Green tea, for example, is not supposed to be brown when steeped since it undergoes minimal oxidation. Yellow tea and white tea are the least oxidized types of tea, meaning the patches of brown they present in the liquid is minimal. On the higher end of the oxidation process, black tea is fully oxidized, so you should expect to see a deep brown characteristic in the liquid when you brew it.

Learn more in our explainer on is green tea matcha?

2. Longer Exposure To The Sun

The change of color in tea also comes from its exposure to the sun. Most green tea varieties should be grown in the shade to ensure the leaves don’t come in full contact with sunlight.

The reason why tea plantations should have a decent setup to cover from sunlight is to produce a milder flavor with less astringency, more umami, and more chlorophyll. Chlorophyll is the catalyst that results in a more vibrant green when you brew it.

People working in tea plantation
Changing of color in tea also comes from its exposure to the sun

Otherwise, the tea will lose its signature green color and begin to turn brown. In the tea industry, this process is known as shading. Shading is very popular in the production of Japanese green tea, which usually happens within the last few weeks before harvest.

In today’s market, gyokuro and matcha can be listed as some of the most popular varieties using the shading technique.

3. Poor Brewing Method

Coming third on the list of the reasons why tea turns brown is the brewing method. The color you see on the original leaves in the package is always different from the liquid color when you brew it.

This is a natural reaction when tea hits hot water at various temperatures. Boiling hot water is likely to destroy the initial color of the leaves and make them brown. Alternatively, steeping too long is also another reason, as the leaves release more tannins than they should have.

Depending on the variety, some green tea produces a gorgeous golden, amber, or light brown color. Those types of green tea cultivated at a higher altitude will guarantee a truly green profile as long as you’re able to get the first harvest of green tea. This type of tea is harder to find and costs more, but the result is worth it.

4. Hard Water

Not many people are aware of the water quality they use for brewing. However, hard water that’s infused with a high concentration of calcium is likely to mess up the tannin levels in tea and force it to turn brown.

You will recognize this reaction as soon as the tea rests and cools down. This is when the brownish color slowly takes over the liquid, forming an oily, glossy film on top. With careless cleaning, the firm will be imprinted on the interior or bottom of the cup, leaving it a dirty appearance.

Hard water also messes with the flavor profile. You may or may not notice it but using hard water to boil tea costs its unique taste, especially with loose-leaf tea. You might also be curious about why is tea served hot?

How To Protect Tea From Turning Brown At Home

To avoid any unwanted situations, keep your tea sealed in an airtight container with as little exposure to sunlight as much as possible. Whenever you open it, close it tightly and store it in a dry corner of your cabinet away from any windows.

Popular Brown Teas

Some types of tea are supposed to deliver a brownish liquid when steeped, and it doesn’t have anything to do with the four reasons I listed above. Black tea, Hojicha, Pu-erh, Assam, and Ceylon are some signature varieties.

Black tea is known as one of the most processed tea types due to withering, rolling, oxidation, and drying. For that reason, the brew is supposed to have a darker brown color with a bright red tint.

Hojicha brings a warm brown color to the brew, with the leaves being roasted right after it is harvested. This is a Japanese green tea that aids digestion and helps ease stomach aches.

Pu-erh, one of the best Chinese teas, is a post-fermented tea with a famous aging process. The tea can be aged for many years after being roasted and fermented. Some of the longest-aged Pu-erh can be very costly.

The color, as a result, is dark brown with a unique mellow flavor.

Originating from the northeastern Indian state of Assam, Assam tea is a type of black tea with a gorgeous deep brown color. One of the best things about Assam’s tasting profile is its malty, earthy, and spicy notes.

Ceylon black tea, the pride of Sri Lanka, has some of the best brown spectra I’ve ever seen. Depending on which type you’re using, it exudes a hue of sun-drenched honey or a burgundy brown. Compared to green tea, Ceylon tea has a vastly different flavor, strong and leafy, with notes of chocolate, spice, and citrus.

Why Does Tea Leave Brown Stains On The Cup?

This is a universal problem for tea drinkers worldwide. If not treated correctly, the stains end up staying at the bottom of your cup forever. Tannins or tannic acid are the ones to blame.

Tannins make tea brown, so it dyes your cup in the same way. Tannins are used to dye leather and to make ink, but you don’t want a brown tea cup. 

Tea bag stain in a white mug
Tea stains end up staying at the bottom of your cup forever

Now comes a life-changing question: how to get rid of brown tea stains in the cup? I’ve tried every trick in the book to combat stubborn brown tea stains and found that baking soda is a true lifesaver. 

First, wet the stained cup and dump out excessive water. Then, sprinkle a tablespoon of baking soda onto the stained areas, and let it rest for a few minutes. Finally, scrub it with a damp sponge.

The key here is to make sure your sponge is just slightly damp and not soaking wet, as you want your baking soda to be abrasive.


  • Oanh Nguyen

    Born and raised by a traditional mama-barista, Oanh is a typical Viet coffee aficionado who would spend her entire precious Sunday showing you how to categorize coffee beans just by the looks and smells. She enjoys writing copies about everything drink-related while sipping her favorite rosebud tea.