Fresh ginger ale with lemongrass

This is a ginger ale for grown-ups, a spicy, not-too-sweet, ultra refreshing drink that combines fresh ginger, lemongrass and chilies in a way you’ve probably never had them.
It makes 1 quart of syrup, enough to make at least 10 glasses.  The syrup keeps for weeks, refrigerated

Thanks to Jean-Georges Vongerichten.

1lb fresh ginger root, unpeeled and cut into small dice
2 stalks lemon grass, trimmed and roughly chopped
2 small chilies, stems removed
1 1/2 cups white sugar
soda water
lime wedges

Combine the ginger, lemongrass and chilies in a food processor and process until minced, stopping the machine periodically and scraping down the sides, if necessary.

Place the puree in a saucepan with the sugar and 1 quart water. Bring to the boil over high heat, then reduce the heat to medium and simmer for about 15 minutes.
Turn off the heat. Cool, then strain and chill.

To serve, place about 1/4 cup of the syrup in a glass full of ice. Fill with soda water, taste and add more syrup if you like. Garnish with a lime wedge, then serve