Fever-Tree Elderflower Tonic Water. Made with natural quinine. No artificial sweeteners, flavouring or preservatives. 16.9 fl oz (500 ml). By blending the essential oils from handpicked English elderflowers with the highest quality quinine from the fever trees of the eastern Congo, we have created a delicious variation on classic tonic water. Please recycle. Consumer Comments Call: 1-800-646-6965. www.fever-tree.com.