I used this recipe, invented by Dr. David Fankhauser. Here's a simplified version to cut and paste into your recipe file, though I strongly recommend that you visit http://biology.clc.uc.edu/Fankhauser/Cheese/Ginger_Ale_Ag0.htm for a detailed, step-by-step treatment. (His site also contains also awesome cheese recipes. I'm dying to make yogurt at home now.)
You'll need: 1.5-2tbs ginger, 1c sugar, 1 lemon (optional!), 1/2 tsp regular ol' bread yeast.
- Put sugar and yeast in an empty 2L bottle (using a funnel, if you have the luxury). Add the ginger, then lemon juice, then fill to the neck with water. Cap it.
- Leave in a warm place until the bottle feels pretty hard from the pressure-- should take 24-48 hours (or less!) but don't leave it out too long. It'll explode.
- Refrigerate to slow/stop the fermentation, and enjoy!