The primary differences in nutritional components between cold-brewed and hot-brewed tea lie in the rate and total amount of certain compounds dissolved from the tea leaves, as follows:
Antioxidant activity: Cold-brewed tea better preserves beneficial substances in the tea, such as polyphenols, due to reduced damage to the tea leaf cell structure by high temperatures. Some studies show that cold-brewed tea has stronger antioxidant activity than hot-brewed tea.
Caffeine content: The dissolution of caffeine is significantly influenced by temperature; it dissolves quickly at high temperatures but very slowly below 60°C. Therefore, cold-brewed tea typically contains less caffeine, making it suitable for those sensitive to caffeine or concerned about its impact on Sleep.
Polyphenol dissolution: Polyphenols still dissolve relatively well at lower temperatures. Due to the longer brewing time, polyphenols and other beneficial substances in the tea leaves dissolve in cold-brewed tea. However, the relative caffeine content is greatly reduced, while the relative content of polyphenols and Theanine increases, resulting in a tea with virtually no bitterness but a prominent aroma and a generally sweet taste.
Taste and color: Compared to hot-brewed tea, cold-brewed tea usually has a sweeter taste and a lighter color. This is mainly because high temperatures easily dissolve components like theaflavins and caffeine, giving the tea a bitter taste.
Nutrient retention: Since cold brewing avoids the destruction of tea leaf cell structures by boiling water, some nutrients like vitamins and polysaccharides may be better retained.
Theanine dissolution: Theanine, which imparts a sweet taste, dissolves quickly even at low temperatures. Therefore, cold-brewed tea contains more theanine, contributing to a sweet taste.
In summary, both cold-brewed and hot-brewed tea have their own characteristics. In terms of nutritional components, cold-brewed tea may have an advantage in preserving Antioxidants and have lower caffeine content, leading to a sweeter taste. However, this does not mean that cold-brewed tea is superior in all aspects, as different brewing methods suit different populations and personal preferences.