missing dimension of flavor.
The ideal water has a moderate mineral
content, and a pH that is close to neutral, so
that the final brew will have a moderately acid
pH of around 5, just right to support and
balance the other flavors. Some bottled spring
waters are suitable (Volvic is used in Hong
Kong). Many municipal tap waters are
intentionally made alkaline to reduce pipe
corrosion, and this can reduce the acidity and
liveliness of both tea and dark-roasted coffee
(light roasts contribute plenty of their own
acid). Alkaline tap water can be corrected by
adding tiny pinches of cream of tartar —
tartaric acid — until it just begins to have a
slightly tart taste.
Caffeine NumbersDaily caffeine consumption in milligrams
per capita, 1990s