Any confusion is further enhanced by the common practice of discarding the first extract when brewing green tea and by strong beliefs as to the optimal temperature for tea extraction often without justification or measurement and local differences, suggesting culture is an important factor in this choice. Ĭommon beliefs about tea and brewing time include both that brewing the tea for a short time reduces caffeine extraction and that caffeine is released first. It is estimated that around 2.25 billion cups of coffee and 6 billion cups of tea are consumed per day. ![]() To effectively change the ratio of the components using the extraction time would require using accurate times of less than 3 minutes and accurate temperatures unusual in a home environment.Ĭaffeine is often called the world’s most consumed legal drug, with caffeinated beverages being some of the most popular drinks in the world. A difference in total extraction efficiency of both components together was noted too. Although the difference in relative concentration was small, the range of brewing temperatures tested was only 20 Kelvin, so it seems possible to increase this difference. At different temperatures, a significantly different ratio between caffeine and colour compounds was observed. ![]() Results showed that the extraction of the two components of interest had different half-lives, with an initial large variation of the ratio between them rapidly reaching a quite constant value. To test these beliefs, we investigated the effect of brewing time and temperature on the colour intensity and caffeine content of the extract of one type of black tea. Various beliefs are common about the extraction of soluble compounds from leaf tea, suggesting that cold brewed tea or tea brewed for a shorter time than usual may contain a higher polyphenol-to-caffeine ratio, a selling point due to the potential health benefits of polyphenolic compounds.
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