This is what you need: 1,5 dl sugar (about 130 grams), 2-3 tbs finely grated fresh ginger, juice from 1 - 1 1/2 lemon (optional), 1/4 tsp dry yeast, water.

Before you grate the ginger, use a teaspoon to remove the peeling, that way you don't cut away big chunks of perfectly fine ginger.

Mix ginger and lemon juice.

Add the ginger and lemon to the sugar and yeast. This recipe gives about 1,5 liters, so you can blend all the ingredients in a 1,5 litre soda bottle and add water until there's a 2-3 cm gap of air left (I didn't have a soda bottle so I mixed the ingredients in a plastic container).

Shake until the sugar has disolved.

As I didn't have a soda bottle I had to use empty Grolsch bottles - looks good doesn't it? As I said earlier, make sure the bottles aren't completely full, the yeast needs some space to play around with the sugar.

Leave the bottle somewhere moderately warm - like in the bathroom and forget about it for a day or two. Then put it in the refridgerator for a day. This recipe should make ginger ale with an alcohol percentage of staggering 0.4, not something you bring to a party, but very tasty!

Source: http://imgur.com/gallery/NLf5A