How should soda made with "ginger bug" smell/taste? I recently fermented a ginger soda using a ginger bug that I made. The bug seemed good to me - no funky mold growing on it, and it fizzled when I stirred it. The soda I made was good, but tasted extra "yeasty" and had spots on top that I couldn't differentiate between fizz or small colonies. 

Is this how a fermented soda using a ginger bug should taste, and if not any suggestions on what went wrong? 

Ginger bug

250 mL (filtered) water + 3 tablespoons grated ginger (skin on) + 3 tablespoons sugar

Contents were mixed in a jar, with a lid placed on top but not screwed shut. Left at room temperature for 5 days, with daily feedings of 1 tablespoon ginger and 1 tablespoon sugar, as well as frequent mixing. 

Soda

120 mL ginger syrup + 240 mL filtered water + 1 tablespoon ginger bug liquid

Contents poured into swinglock bottle, left at room temperature for 2 days. Bottle was "burped" after 1 day to relieve pressure.
if it tasted extra 'yeasty' you're probably just fermenting too far. try starting with less of the bug per liter of liquid, and stop the fermentation sooner.