Tonic water is not a complex product, it is essentially quinine, carbonated water, and sugar. Tonic water has a bitter taste that comes from quinine, though usually now has a significantly lower quinine content. and often sweetened. Today, tonic water contains far less quinine than a century ago, but it is still part of the bitter taste that is perfect for cutting the flavours of hard liquor. It is often used in mixed drinks, particularly in gin or Vodka. Here, you will discover a wide variety from leading manufacturers including Schweppes, Fitch and Leeds, Barker and Quin and Swaan.