Sometimes, in my nonvirtual life, I'm a copy editor. So what I'm about to say may be shocking.
Accuracy isn't always the most important thing.
(Actually, it's probably more surprising than shocking, unless you too are a sometimes copy editor.)
If you really think about it, though, it's true. Text can be over-edited; words so scrutinized that the emotion and life behind the piece is completely lost. Maybe that's why the concept of electronically precise brewing for something as ancient and as basic as tea just seems off to me.
I do still own a rotary phone, though, so perhaps I'm not the most impartial reviewer of electronic products.
The correct water temperature is crucial for the type of tea you're making (see these brewing guidelines). But my method is usually a finger in the water: If it's too hot for me to do that, it's too hot for green tea.
But there is a more lyric- and less painful- method to calculate water temperature, eloquently codified in Lu Yu's Cha Jing, or The Classic of Tea. Written in China around 770, this is the oldest book on tea. Author Lu had a fascinating life: after a peripatetic youth (involving an orphanage, an escape from a Buddhist monastery and a traveling opera troupe), he decided to embark on a tea quest to definitively compile its history, production and techniques in one book.
The publication of Cha Jing led to Lu's widespread recognition- and two requests for appointment to the imperial court (both of which he turned down)- as well as his posthumous designation as the patron saint of tea.
So even though he wrote during the stone ages, this man knows what's he's talking about. Water still behaves the same. Here are the Cha Jing's descriptions, which use visual cues to indicate temperature:
- "column of steam steadily rising": a pillar first appears from the surface, 170°-180°F (for green teas)
- "fish eyes": large bubbles first break the surface of the water, 180°-200°F (some greens, oolongs)
- "string of pearls": tiny, champagne-like streams of bubbles circle to the surface, 190°-200°F (some oolongs, black)
- "turbulent waters": a full, rolling boil, 200°-212°F (pu'er)
Tea is suitable to be a beverage for its chill nature, especially for those who prefer moderate, plain living. In case of thirst, melancholy, headache, weariness of eyes, or trouble in limbs and joints, a few of sips can be sweet dew from heaven. Cha Jing, Lu YuYou said it, Lu.