Taste is perceived in the human mouth, while aroma is detected by the human nose. The combination of taste and aroma gives rise to what we commonly refer to as flavor.
The formation of tea aroma occurs through four crucial manufacturing stages: starting with the fresh green leaf stage, followed by withering, fermentation after rolling, and finally during firing in the made tea stage.
During the withering and fermentation stages of tea leaves, various aroma compounds emerge.
The fermentation process in tea manufacturing produces floral tea aroma compounds, which significantly influence the quality of each tea type, especially oolong and black tea.
Once the tea is poured, its fragrance depends on the degree of fermentation. Tea leaves should not carry undesirable odors such as carbon, parched, or smoked scents, as these indicate low-quality leaves. Green teas should have a light, fresh, and soothing fragrance, ranging from a light orchid to a chest-nutty aroma. On the other hand, black tea should exude a sweet, floral fragrance that lingers.
Research into identifying tea aromas has been conducted for over a century, resulting in the discovery or isolation of more than 600 volatile compounds.
Among these compounds, the most significant ones include limonene, phenylethyl alcohol, linalool, geraniol, trans-2-hexenal, phenylethyl acetaldehyde, alpha and beta-ionone, isovaleric acid, benzoic acid, o-cresol, dimethyl disulfide, and n-ethylformyl pyrrole, along with 18 esters and lactones.
Overall, tea can be categorized into three aroma degrees. Some teas possess a unique primary aroma influenced by growing conditions.
The secondary aroma builds upon the primary one, and its strength or subtlety depends on the production process, including the storage of plucked leaves and fermentation.
The tertiary aroma develops as tea is stored, primarily applicable to aged teas like Pu-erh, where exposure to air mellows the tea and imparts an earthy scent.
Tea Aromas Explored
