TEA101 – How Acid Is Your Tea?
We rarely think of acidity in tea, but it’s actually interesting.
First, some basics from “Salt, Fat, Acid, Heat: Mastering the Elements of Good Cooking” by Samin Nosrat.
Anything that sits lower than 7 on pH scale, is technically acid (lime pH is 2, red wine vinegar pH is around 3).
Both salt and acid heighten our pleasure in food. But they work differently: “salt threshold is absolute, acid balance is relative”. Acid BALANCES other flavours.
For WINE, acidity is a big deal. As grape matures, acid falls from around 3% to 1%, and sugars rise from 4% to almost 25%. The key: harvest the grapes at the moment of the right balance of acidity and sugar.
TEA we drink has two sources of acidity: tea leaves and water.
At a very basic level, acidity of dry leaves will be determined by oxidation – the process which starts spontaneously when the enzymes in the picked leaves come in contact with oxygen.
Oxidation is NOT fermentation, though very often both terms are liberally interchanged. Fermentation process needs a trigger and does not always require oxygen. The classic case of fermentation is dark tea, including ripe Pu’Er (Shu Pu)
For all other teas, it is correct to talk about oxidation.
White teas and maocha (the “raw material” for Pu’Er) are about 10% oxidized due to withering.
Next come oolongs. The diapason is large: from 30-40% for guys like Tie Gyan Yin to almost 80% for Rock teas from WuYi mountains.
Black teas are fully oxidised.
Implications for TEA:
– addition of sugar (a no-no for me) works better for black teas than for green
– think about acidity balance between water / tea leaves & food
– green teas don’t age well – same as low acidity wines.
Do you have any other thoughts? Please let me know