Brewing tea requires specific water temperatures and precise steeping times. While you can track steeping time using your smart phone, you cannot dip your smart phone into your cup to see how hot the water is. It's easier to interpret water temperature based on how your tea turns out, then apply what you learn to future cups of tea.
Most black teas are best steeped in near-boiling (195-210°F) water. A typical water dispenser doesn't make water quite this hot, but it comes close. When brewing black tea in the office, swirl hot water in your mug to heat the mug first. Dump that slightly-cooled water out, then immediately add your tea ball and pour fresh hot water right onto the tea. This helps ensure the hottest possible steeping.
Oolong is easy to brew in the office; most hot water dispensers produce exactly the right temperature water for it (about 185°F). You'll want to follow the same procedure as for Black Tea, but you can get away without heating your mug first.
While a dispenser's water is slightly too hot for white tea, that's ok! You can get the extra heat to transfer to your room-temperature ceramic mug, creating water that is the right temperature; 160-175°F. So - pour the hot water in your mug, wait until the mug is hot to the touch, then add your white-tea-filled tea ball and steep away.
Green tea is difficult to brew even with the right equipment. I've ruined many a cup! Here's one way to avoid overcooking those delicate leaves in the office:
- Put your green tea in a tea ball in your room-temperature ceramic mug.
- Pour COLD water into your mug until it is about 1/6 or 1/5 full. Learning exactly how much cold water is right for your mug and your tea may take a few tries.
- Swirl the cold water around the tea ball, soaking the tea. This helps protect the tea against the near-boiling water you're about to add.
- Pour HOT water into the mug, filling it the rest of the way, making sure to aim the stream of water away from the tea ball.
- The green tea should now be sitting in roughly the correct temperature water (around 150°F, plus or minus). Remember to not oversteep.