Slice the ginger as thinly as possible. It can’t be too thin, so use a sharp knife.
Put the ginger slices in a nonreactive pot, add enough water to cover the ginger, and bring to a boil. Reduce heat and let ginger simmer for ten minutes. Drain, and repeat, simmering the ginger slices one more time.
Mix the sugar and 4 cups (1l) water in the pot, along with a pinch of salt and the ginger slices, and cook until the temperature reaches 225ºF (106ºC).
Remove from heat and let stand for at least an hour, although I often let it sit overnight. To coat the slices with sugar, gently rewarm the ginger (the syrup will drain easier if warm) and strain the ginger through a colander or strainer. Let it drain thoroughly, 30 to 60 minutes.If saving the syrup for another purpose, strain the ginger over a bowl. The ginger can also be stored in the syrup, in a jar.
Toss the drained slices in additional granulated sugar. Shake off excess sugar, and spread the ginger slices on a baking sheet or cooling rack until they’re somewhat dry. The sugar can be reused in a batter or ice cream base, or for another purpose.