I've made tons of ginger beer (often just like this http://ieatfood.net/2009/12/18/real-ginger-ale/ ), I've tried various different recipes, and they all come out quite nicely. But I want a ginger beer that's SHARP. Everything I make has a nice ground gingery mouth feel, where as ginger beer I buy (like Fentimans, Bundaberg) tends to be a lot sharper for a better "Dark and Stormy" taste.
It's not lemon. It's not pineapple.
How do I make it sharp?