Gather the grated ginger into your hands and squeeze over a pitcher to extract the juice*.
Add the mint to the pitcher, and use a wooden spatula or wooden tamper to give the mint a mash. We want to bruise the mint leaves slightly to extract their flavours.
Add the lemon juice, water, ice cubes, and syrup. Stir, add more syrup if the drink tastes too tart, and serve immediately.
Notes
* Discard the pulp. For a more subtle ginger flavour, simply cut the ginger into slices and add it to the pitcher, instead of grating and squeezing.Recipe adapted from Pick up Limes