Peel the ginger root and slice into 1/8 inch rounds.
Place the ginger slices in a large 6 quart sauce pot. Add the water. Bring to a simmer. Cover and simmer for 30 minutes to soften the ginger.
Remove the lid and check the liquid levels. There should be approximately 1/4 - 1/3 cup of water in the bottom of the pot. If needed, scoop out some water with a ladle, or add water, to make sure you have about ¼ cup in the pot.
Stir in the sugar and salt. Bring the sugar syrup to a simmer. Simmer, stirring regularly, for 15-20 minutes, until the syrup starts to crystalize. The color will range from pale cream to golden. Remove from heat and stir in the vanilla extract.
Set out a baking rack. Spray with nonstick cooking spray. Use tongs to move the ginger pieces to the rack, spreading out in a single layer.
Allow the ginger to rest for 2-4 hours, until all the pieces are dry.
Place in an airtight container. The ginger candy will last for at least 1 month if kept in a cool dry place.
Vanilla extract adds a nice balancing note to the candy. You can also add orange extract.