Why is :PREMIUM Fructose Fuel so much sweetener than my traditional custom blend?

A: Fructose is naturally very sweet. PREMIUM Frucose Fuel contains a 2:1 ratio of glucose to fructose. The result is a sweeter taste profile than traditional INFINIT Custom blends. 

If you don’t like a sweet drink, then you may be better off sticking with a traditional Custom Fuel + Hydration blend where the flavor is completely customizable, and the overall sweetness can be dialed down.