Rainbow film on your tea: Harmless reaction explained
Is the rainbow film on tea safe to drink? This phenomenon raises many questions and uncertainties. Is such a beverage still safe? Let's take a closer look.
3 September 2024 16:27
Tea is one of the most popular beverages in the world, but sometimes it can surprise with its appearance. On the surface of freshly brewed tea, foam or an oily film resembling scum can appear, shimmering like a rainbow patch. Many people wonder whether such phenomena are normal and whether they affect the quality or safety of the tea. The answers to these questions are simpler than they seem, and importantly – they dispel any doubts related to this popular beverage.
Where does the rainbow film on tea come from?
The rainbow film on the surface of tea results from a reaction between the polyphenols in the tea leaves and the calcium carbonate present in the water. The harder the water, the more calcium carbonate it contains, and the more pronounced the film on the tea will be. Although this iridescent film may look unappealing, it is completely natural and poses no health risk.
Is tea with a film safe to drink?
Yes, tea with a film is completely safe to drink. Both the foam and the film are natural phenomena and do not affect the taste or health properties of the tea.
So why does this film form?
- Hard water: The higher the calcium carbonate content, the more pronounced the film.
- Type of tea: Some types, especially black tea, are more prone to forming a film.
- Brewing method: Pouring tea with a strong stream from a height promotes foam formation.
How to prevent film formation?
Although the film on tea is harmless, not everyone likes its appearance. If you want to avoid this phenomenon, you can:
- Filter the water: This will decrease the calcium carbonate content in the water and limit film formation.
- Add lemon: Lemon juice reacts with calcium carbonate, inhibiting film formation.
- Brew tea at a lower temperature: A lower water temperature reduces the intensity of the reaction between the polyphenols and calcium carbonate.
The foam and rainbow film on tea are natural phenomena that should not cause concern. They result from chemical reactions between the tea and water substances. Although they are not harmful, you can apply a few simple tricks if you want to avoid their appearance.
