Combine ginger, water, and sugar in a saucepan.

Bring the mixture to a rolling boil over medium-high heat.

Reduce heat to low and simmer.

Continue simmering until the mixture reduces into a strong syrup.

Strain the syrup to remove the ginger slices.

Refrigerate the syrup to thicken.

Mix 1 part syrup with 7 parts seltzer water.

Adjust the amount of syrup based on your preferred strength.

Add lime juice to taste.

Toss the remaining ginger slices in sugar.

Place the sugared ginger slices in a warming oven.

Dry the ginger slices in the oven to create crystallized ginger.