A cup of tea can give you a moderate jolt of caffeine to start your day or keep you focused. After steeping your bag once, though, you might be wondering if a second steep could pull out more of the caffeine or other components that made your cup of tea so invigorating the first time around. Whether a second infusion boosts caffeine depends on a few different factors, but in most cases you are probably better off just using a new bag.
Caffeine in Tea
All types of tea, except for decaffeinated teas, contain caffeine. However, the total amount depends on the specific type of tea. Green and white teas have the least caffeine, about 9 to 50 milligrams per 8-ounce cup. The same amount of black tea has 42 to 72 milligrams. With such a wide range, the number of times you steep a bag matters far less than the specific bag of tea you use in the first place.
Steeping and Reusing
While a slight bit of caffeine remains in the bag after the first steep, it usually isn’t worthwhile to reuse the same bag to get that slight bit out. Most of the caffeine content leaves the tea bag with the first infusion, and each subsequent steep releases less and less caffeine. In fact, if you want to limit the caffeine in your tea, you can steep it for 30 to 60 seconds and dump that first infusion to get rid of the majority of the caffeine content before placing the bag in a new cup of hot water. If you’d rather get all of the caffeine you can out of a single bag, lengthening the time you steep it may be more effective. The same thing applies to the beneficial antioxidants and phytochemicals in tea leaves, which exit the tea bags along with the caffeine.
The water temperature has an effect on how much caffeine your tea bag retains for the second steep. Higher steeping temperatures are generally recommended, but if you steep your tea in cooler water, the second steep may actually be higher in caffeine. A 2007 study in the “Journal of Chromatography” found that tea steeped at 85 or 100 degrees Celsius, or 185 to 212 degrees Fahrenheit, releases most of its caffeine in the first infusion, while tea steeped at 70 degrees Celsius, or 158 degrees Fahrenheit, releases more caffeine on the second infusion. However, the total amount of caffeine is lower in a cup of tea steeped at lower temperatures than one steeped at high temperatures, so using cooler water gives you a lower total caffeine dose.
Other factors can affect the level of caffeine in your cup of tea as well. The origin of the tea, the preparation method, the growing conditions and the amount of oxidation the tea leaves have undergone are all important factors. The tea in tea bags is more oxidized than loose-leaf tea because it has been crushed into tiny pieces, so the caffeine content is higher than when using loose tea. If you want to maximize the caffeine content of your tea, choose a black tea that is highly oxidized and steep it for a long time instead of reusing the same bag more than once.