Some people from work invited me to the Dominion Tavern a week or two
ago. I was persuaded to try the gin and tonic, as I was told that the tonic
water was homemade.
I ordered one. The drink that came was orange in colour and looked
vaguely like tang. In other words, it did not look like a gin and
tonic. It tasted, however, unmistakeably like a gin and tonic - a
rather good gin and tonic at that, and this comes from a guy who's not
particularly enthusiastic about gin and tonics.
I was inspired to try this out myself. The active ingredient in tonic water,
giving it its characteristic bitter taste, is a substance called
quinine. Back in the day, quinine was used as a painkiller and malarial
treatment. In the (rather large) quantities required for medicinal purposes,
it was known for its strong, unpleasant bitterness, so people started mixing
it with gin to make it more palatable. As time wore on people started
consuming quinine less and less as a medicine and more and more as a
flavouring agent, especially in the quantities used for modern day tonic
water, which is many times less than required to receive any therapeutic
benefit (you'd have to drink something like 8L of modern day tonic water to
approach even just one dose of malarial treatment).