Nepali tea teas like green tea, oolong tea, white tea and hand rolled tea fall under the category of orthodox tea. In Nepal, orthodox tea is produced and processed in the mountainous regions of Nepal at an altitude ranging from 3,000 – 7,000 feet above the sea level. There are six major districts, primarily in the eastern regions of Nepal that are known for producing quality orthodox tea, which are Ilam, Panchthar, Dhankuta, Terhathum, Sindhulpalchok and Kaski. Orthodox tea in Nepal is characterized by four flushes:- Crush, tear, curl (CTC) tea is a method of processing Assam variety "(Camellia sinensis" var. "assamica)",
Camellia sinensis catalyzes the conversion of 7-methylxanthine to theobromine, as well as the final conversion of theobromine to caffeine. Camellia sinensis Camellia sinensis is a species of evergreen shrub or small tree whose leaves and leaf buds are used to produce tea. It is of the genus "Camellia" () of flowering plants in the family Theaceae. Common names include "tea plant", "tea shrub", and "tea tree" (not to be confused with "Melaleuca alternifolia", the source of tea tree oil, or "Leptospermum scoparium", the New Zealand Tea Tree). "Camellia sinensis" var. "sinensis" and "Camellia sinensis" var. "assamica", are two major varieties grown today.