Tea Leaf Drying Time

Tea Leaf Drying Time (Camellia sinensis)

Turning fresh leaves of Camellia sinensis into tea runs through three phases, one after the other, and you can estimate the total with T_total = t_withering + t_oxidation + t_final_drying. The first phase, withering, runs 12–18 h at 25–30 °C with relative humidity around 60%. It drops the moisture from roughly 80% down to about 55% and leaves the leaf supple enough to roll.

Once withered, the leaves get rolled, which breaks the cell walls and releases the enzymes inside. Then comes fermentation/oxidation. Black tea sits for 2–3 h to oxidize fully; green tea gets 0 h, since steaming or pan-firing shuts the oxidation down before it can start. Final drying runs at 80–90 °C for 15–20 min in conveyor or tray dryers, pulling the moisture below 4% so the leaf keeps in storage. In Brazil the main growing area is Registro/SP (cha-do-Brasil), and the parameters used internationally come from sources like the Tea Research Institute of India (TRA) and GIE-Tea.

Applications

Tea processors, agroindustry technicians and food-science students use this to lay out batch schedules and size their drying equipment. It also helps them keep an eye on final moisture, which decides shelf life and keeps aflatoxins at bay, and to tell apart how black, green, oolong and white teas are processed.

FAQ

Sun, shade or oven drying — which is best? Shade or a controlled oven (estufa) holds on to chlorophyll and polyphenols better. Direct sun is quicker but it wears down the aroma and color, so you only see it on a few artisanal teas.

What is the target final moisture? Aim below 4%, ideally 3%. That keeps the tea safe in storage and stops mold from taking hold, which lines up with ABNT and Codex Alimentarius standards.

Why does green tea skip fermentation? The enzymes get shut off right away, by steaming in Japan or pan-firing in China, so the catechins stay put and oxidation never happens. That is the chemical and sensory line that separates green tea from black.