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Why Does Tea Foam — The Answer

Why Does Tea Foam — The Answer

If you’ve been making tea for any length of time, you’ve undoubtedly noticed that it foams a little bit.

Most people wouldn’t care much about it, but curious minds question why their tea is foaming.

Many people believe that this tea foam is unsafe to consume and throw it away.

Alternatively, many consider it as a quality issue with the tea leaves and discard them completely.

But is there something in particular that causes the tea to become foamy, and is there anything wrong with tea if it foams excessively?


Why does tea foam?

There are many components in your tea that cause it to foam. Naturally, present elements like Tannins, Pectin, and Saponin are a few of the culprits. Other reasons for foamy tea include microwaving your tea or air getting trapped in it. 


How is tea foam created?

As mentioned earlier, tea foaming cannot be linked to a single factor. Instead, there are multiple reasons for it. 

Components like Tannins which are, plant polyphenols are abundantly found in Black teas.

They are known as natural foaming agents. Moreover, tannins give teas their characteristic bitter taste and brown coloring. 

Pectin is yet another natural element found in teas. They are natural stabilizing agents found in most plants. Pectin is also responsible for the tea pearl phenomenon.

This occurrence is characterized by the appearance of bubbles that appear on top of the tea surface and do not pop.  

Saponin is a glycoside responsible for protecting the tea plant against pathologies.

This component is one of the naturally occurring elements which are released on top of the tea leaves.

Saponin in Matcha tea is well known to cause foaming as it is present in higher quantities within this tea.

The rolling technique used to produce some teas also increases the amount of Saponin released by the tea leaves and results in more foaming.

Other natural elements like Amino acids, fatty acids, and denatured proteins are also known to cause tea foam. The higher the amount of these elements in your tea, the greater the quantity of foam produced will be.

Besides tea foam being produced naturally, air finding its way into your teacup can also influence the amount of tea foam. 

The most common method is during the pouring of water.

There is a good probability that air gets accidentally pushed into the tea mixture depending on how you pour the water onto the tea leaves or tea bag.

Some of the air will adhere to the tea, the teabag, and the brewing vessel’s walls, forming tea foam.

Additionally, one of the most prevalent reasons for foamy brewed tea is trapped air.

The air might become entrapped inside the tea leaves or the tea bag you use.

When this air is expelled, it might result in the formation of bubbles on the surface of your tea.

Lastly, we have dissolved gas. Because gases may dissolve in water, they could be causing your tea to bubble. If any of the dissolved gases escape during the brewing process, they may cause frothy bubbles to form on the surface. 


Factors affecting the amount of team foam produced

The quantity of foam that forms on the surface of your teacup is primarily determined by the amount of foaming agents dissolved and the quantity of gas that is present in the brewing mixture. However, there are other factors that also play a minor role in the tea foaming process.


The temperature of water used for brewing

The water temperature while brewing your tea might influence foam formation. You should anticipate more or less foaming depending on whether you’re brewing your tea with hot water or cold water.

When water becomes excessively hot, it may make it easier for contents like tannin and pectin to dissolve, resulting in more foam. This also explains why tea foams when the microwave is used.


The type of tea you use

While all teas contain foaming compounds, the concentrations of foaming compounds vary naturally. Because Matcha is high in Saponin and Black tea leaves are high in tannin, they will produce more froth.

Furthermore, heavily roasted teas, for example, will have fewer of these molecules. As a result, they will create less foam.


The presence of additives in your tea

Tea may include ingredients that contribute to the formation of foam. Earl Grey, one of the most popular teas, has an ingredient that not only makes it taste like soap but also makes it froth a lot more.


The size of your tea leaves

Tea leaves that have been broken are more likely to produce a large amount of foaming. This is due to the fact that more of the naturally present foaming agents will be extracted during the brewing process.

Because broken tea leaves have a larger surface area, the chemicals will dissolve more quickly. To avoid tea foaming, use whole tea leaves rather than tea bags.


Foreign substances in your tea

If foreign components have been added to the tea, it may bubble up more than usual. For example, you may not have washed out your teapot as well as you believed. This will result in more foaming when brewing tea in the kettle.


Microwaving your tea 

The primary process of foaming while using a microwave is due to the fact that the water you’re using has been overheated. As a result, a lot of heat might produce a lot of foam. The microwave is raising the temperature of the water over its boiling point.


Frequently asked questions about why does tea foam


Can tea foam be caused by expired tea leaves?

There is no such thing as expired tea. Tea simply, over time, loses its taste and aroma if not stored properly. Hence foaming due to tea leaves is a natural occurrence that is not linked to tea leaves expiring. 


Is the tea foam safe to consume?

Tea foam is safe to consume as it is not associated with pesticides in tea leaves or tea leaves going bad. These reasons are all assumptions with no facts backing them up.