我們都知道喝咖啡會攝取大量咖啡因，而咖啡因也是一種中樞神經的興奮劑，藉由攝取咖啡因達到提神的功效，但如果喝得太多，往往會導致有心悸或者睡不著等現象發生。但是，你知道茶葉中一樣也存在咖啡因嗎？

根據2005年Journal of Food Science及2008年Journal of Analytical Toxicology的研究，茶中的咖啡因也會因為製作方法的不同而有所不同，雖然每款茶葉因為製程和環境因素有所差異，但大家可以透過以下介紹來大致了解茶葉中咖啡因的含量。

如果每100ml的咖啡所含有的咖啡因有100mg，那麼茶葉咖啡因含量由高而低分別是：

咖啡 (100mg)

抹茶 (47mg)

紅茶 (37mg)

烏龍 (31mg)

綠茶 (31mg)

普洱 (21mg)

根據前農委會茶業改良場場長、台大園藝暨景觀學系教授陳右人所述「茶的咖啡因含量與茶種、茶葉的老嫩、茶的製程都有關係」，越嫩的茶葉咖啡因含量越高，越老的茶葉反之越低。另外，在茶葉製作過程中，「烘焙」的工藝會大大降低茶葉裡的咖啡因，茶葉中的烘焙工藝是藉由高溫所產生的「梅納反應」讓茶產生變化，因而得到不同的風味，同時，咖啡因也會因為高溫烘焙而減少許多。

茶葉沖泡時間及溫度亦是影響咖啡因含量釋出的重要因素，溫度越高則咖啡因釋出的越多，浸泡時間越久則咖啡因釋出的也越多。

總結而言，如果希望攝取越低含量的咖啡因，那可以選擇烘焙過的茶葉，或者使用冷泡的方式來萃取。

 

低咖啡因含量系列：
烘焙工藝系

低咖啡因沖泡教學：

 

 

As we all know, coffee contain certain amount of caffeine, a natural stimulant, which we highly rely on in our daily lives. However, it is undeniable that consuming too much caffeine can cause some negative effects on sleep, anxiety, etc.. 

Do you know that TEA also contain caffeine?

According to "Journal of Food Science"(2005) and "Journal of Analytical Toxicology"(2008), the amount of caffeine in tea can vary between different types of teas because of spices, environments and processes. The researches also point that every 100ml of coffee can contain 100mg of caffeine, and amounts of caffeine in teas are shown below:

matcha (47mg)

black tea (37mg)

oolong tea(31mg)

green tea (31mg)

puer(21mg)

Besides, some kinds of tea, such as oolong,  which has been roasted in the process, contains lower amount of caffeine. With the high temperature and long period of roast, the amount of caffeine in tea reduces.

In addition, the method of brewing also matters. The higher temperature of water is, the more amount of caffeine will be extracted. At the same time, the longer period of brewing tea is, the more amount of caffeine will be extracted. 

If you are looking for low caffeine tea, you can try roasted oolong tea and brew tea with cold water.