The taste of tea is formed by the contribution of non-volatile metabolites. The prevailing view is about the bitterness of tea originates from alkaloids (caffeine) and tea polyphenols, astringency from tea polyphenols (catechins), and umami taste from free amino acids, especially theanine. In addition to volatile metabolites, the content of these non-volatile metabolites changes significantly during tea processing, resulting in a diversity of tea flavors. In this chapter, we focus on the effects of key processing steps on taste quality and metabolites in different tea types, and some novel processing methods are also described.