Too much water could make the batter too runny, and too much flour could make the batter too thick. For a single roll, one egg, half a cup of cold water, and a cup of flour should work just fine.
[header] How to make a shrimp tempura roll [title] Make the tempura batter. [step] Mix the flour, eggs, and cold water. Make sure you put an equal amount of all three of the ingredients.