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?
I've had success using 3-5 lbs of fresh ginger in a 5 gallon batch of ginger soda. I find it's important to very finely cut the ginger (I use a strong blender/food processor). Once I've simmered the ginger for about 15-30 minutes, I strain the pulp into a grain sock and squeeze as much liquid as possible from it. I use my hands to do the pressing (warning: wear gloves), so it's probably not the most sanitary or efficient method, but it gives my soda that Reed's ginger ale burn.
I'm sure there's a better way...
Up front sharpness comes from acidity and to some degree, the level of carbonation. Most soft drinks have citric acid, and some phosphoric acid to create a sharpness to balance the sugar, and have a high level of carbonation (>3 vols CO2)
Getting that sharpness is a balance thing - if you have too much sugar compared to the acid the drink will not be sharp, but of course too much acid and it will not be pleasant.
You can also try using pickled ginger pieces, rather than fresh or ground ginger, along with the pickling juice that'll give a great spicy aroma and some spicy warmth when you drink. I used about 250g of pickled ginger in my last 5 gallon batch and it was almost firey! I carbonated in a keg, to 3.5 volumes CO2 - the high carbonation also creates a pleasant sharpness to the drink.
That kick of ginger typically gets stronger with longer steeping time.
After some experimentation, I'm convinced that the "bundenburg" flavor comes from long steeping and pear juice.
I once made ginger candy. The secret to the spiciness was in heating the ginger, letting it cool and then heating it again. Each heating and cooling cycle added quite a bit more kick to the ginger. I would imagine the same would be true for ginger beer. After the fourth cycle, the ginger was so spicey that I could not eat it!
The longer you heat it, the stronger it is. Don't use the liquid into it's cooled with the ginger in it. Acid and chili pepper or Cayanne help as well, I use cayenne and lime.good luck
A recipe that a friend of mine and I have been playing with includes some cayenne pepper. I really like the taste, and I think it can actually have the effect of making the ginger beer taste more like ginger.
One thing that hasn't been touched on in previous answers.
Look into a water profile that best suits your base beer. I've not looked into it but I'm sure there is an ion you can manipulate to get the ginger character you want to stand out more, much like how gypsum accentuates hops.
My ginger beer gets hotter if I strain the ginger mixture multiple times. So after straining after a simmer of 30 minutes, move the strained ginger mixture into a pan add hot water and boil (5 min). Do this several times (5 times) until strained water runs clearer. It doesn't take more time if you have to top up a 23L drum with hot water.
Maybe try drying your fresh ginger for a week before use the dryer it gets the more heat you get from your ginger root. This trick turned my brew into a really nice spicy ginger hit! Maybe even too spicy, now I do half dried old fresh ginger root with half fresh plump ones. Hope this helps for your ginger bite!
