The Polyphenol Extraction of Tea
Brewing the perfect cup of tea is a delicate exercise in temperature and time management. Unlike coffee, which is relatively robust, tea leaves are highly sensitive to thermal energy. The goal of steeping is to extract aromatic oils, L-theanine, and desirable polyphenols while minimizing the extraction of bitter, astringent tannins.
Thermal Sensitivity by Tea Type
Each 'category' of tea is defined by its oxidation level, which in turn dictates its ideal brewing temperature:
- Green & White (Unoxidized): These leaves are delicate. Boiling water (212°F) will 'scald' them, instantly releasing bitter catechins.
- Oolong (Semi-oxidized): Requires a middle-ground temperature to unfurl the tightly rolled leaves and release complex floral aromas.
- Black & Herbal (Fully oxidized): Requires boiling water to penetrate the dense, withered cell structures and extract bold flavors and deep colors.
The Formula
Tea brewing is generally measured in 'Grams per 100ml' or 'Teaspoons per Cup'. This calculator provides a precise duration and temperature guide based on the specific chemistry of each leaf type.
Steep Time = Base Duration * Leaf Grade Multiplier
The Impact of Water Quality
Since a cup of tea is 99% water, the mineral content of your water is a critical 'ingredient.' Hard water (high in calcium and magnesium) can prevent the tea's flavors from fully extracting and often creates a 'scum' on the surface of black tea. For the best results, use filtered water with a neutral pH.