FEVER TREE CLUB SODA 6.8 OZ. By using soft spring water, bicarbonate of soda and a high level of carbonation, Fever Tree created a delicious soda water with a delicate aroma. Perfect for bringing out the best flavors of the finest whiskies. This premium soda water has a silky smooth texture created by using the finest spring water (which has a low mineral content) and a high level of carbonation. It has no aroma so it can effectively bring to life the flavors of the premium spirit it's being mixed with.