If you look closely when brewing tea, whether steeping at room temperature or in hot water, you will likely see small bubbles appear, creating a froth effect. This happens due to a combination of factors, including the release of natural compounds, water quality, agitation during the steeping process, and the interaction of water with dissolved substances.
Natural Compounds in Tea
- Proteins and Amino Acids: Tea contains proteins and amino acids, such as theanine, that can create bubbles when released into hot water.
- Saponins: Some teas, particularly green and herbal teas, contain saponins—natural compounds that can lower the surface tension of water and cause foaming.
- Polyphenols: These antioxidants, like catechins and tannins, can also contribute to foam formation during steeping.
Tea Quality
- Particles in Tea: Teas with fine dust or powders (e.g., powdered matcha or low-quality tea bags) can create froth as these small particles interact with water, trapping air bubbles.
- Surface Tension of Water: Some teas, especially those with higher fat or oil content (e.g., matcha or teas with added flavorings), can disrupt water’s surface tension, leading to froth.
- Oils or Additivies: If the tea or tisane blend contains natural oils (e.g., from added spices or citrus) or flavorings, these can contribute to frothiness during steeping
- Tea Treatment: I once read a testimonial from a woman in a major tea-growing region who stated she saw so many pesticides sprayed on the plants that she would only ever drink organic tea. Source only organic teas, noting that anything that comes from Japan is by default organic.
Water Quality
- Hard Water: While minerals are naturally occurring in water, municipalities add in things like chlorine and chloramine to purify the water. Additionally, your pipes likely contain lead and other metals. Layer in the fact that the water received into the municipalities’ water systems frequently contains runoff from agricultural processes, leaving traces of pesticides.
Each of these elements, and more, can create more froth because the chemicals are interacting with tea compounds. Quality water is a big deal. Far from being a scare tactic, knowing these facts is your chance to fix many things in your health life.
- Boiling Point: Overboiled or overly aerated water may trap air and enhance foam formation.
Agitation
- Pouring Water: When hot water is poured onto tea leaves or a tea bag, it creates turbulence, trapping air and forming bubbles on the surface.
- Stirring: Stirring or swirling the tea can increase agitation, enhancing froth formation.
Type of Tea
- Matcha Tea: Matcha is whisked to create froth intentionally. Its fine powder and high protein content make it froth easily.
- Herbal Teas: Herbal teas with naturally foamy compounds, like saponins, froth more when steeped.
- Green and Oolong Teas: Due to their composition and processing methods, these may be more prone to producing white foam.
Is Frothing a Problem?
Frothing is typically a positive result of tea steeping and doesn’t affect the quality or taste. It’s more common in certain teas (e.g., green tea, matcha, or herbal infusions) and often disappears as the tea settles.
While the froth itself does not affect quality or taste, the contributing factors may be. If the frothing seems excessive or unusual, it may be due to impurities or additives in the tea or water quality.
Precautions
Summary
Use high-quality tea leaves in filtered and preferably Electrolyzed Reduced Water (ERW).
Water: Anyone who knows me knows I’ll bring up water first. Those in the USA should check what’s in their local water supply via EWG’s Tapwater Database. If what you see scares you, check out the certified and medical-grade filters and water ionizers in ImmerHealth’s store. Also, please contact us so we can help you navigate this topic, it’s a hard one to get used to.
Tea: Not all tea is made alike. Many of the bagged teas have older leaves that are finely ground. Additionally, the teabag itself may not be of good quality and, when exposed to hot water, may be releasing microplastics into your cup.
There is no need to worry about foam resulting from agitation or specific tea types.
Sources:
https://www.chefsresource.com/why-does-my-tea-have-white-foam/
