We had a thread about this a month or three ago - we've been
experimenting and I'm reporting in:

Our most recent batch was about 1 cup of peeled, chopped ginger root,
cooked in 3 cups of water and 3 cups of sugar for 90 minutes. This made
great tasting ginger syrup. Our previous attempts, using less simple
syrup, gave us ginger syrup that wasn't sweet enough, although the
candied ginger from both processes was the same to our taste. So:

3 cups of water
3 cups of sugar plus more to coat ginger pieces at end
1 cup peeled, sliced (about 1/4" thick) ginger root.

Combine 3 cups of sugar plus the water in a pot, heat on high, stirring
every minute or two, until the sugar is completely dissolved and the
mixture is boiling.

Add the peeled, sliced ginger, bring back to a simmer, let cook for 90
minutes or even a bit more, stirring once in a while (every 15-30
minutes or so is plenty).

Put a large enough bowl under a strainer, pour everything from the pot
into the strainer, let the ginger drain for a few minutes, shaking the
strainer to help get rid of excess liquid.

On a piece of parchment paper, sprinkle sugar, spread out ginger pieces
from strainer, turn over once or twice to be sure you've coated all of
the ginger pieces. Ginger will be soft - let dry this way as much as
you like, move to storage container of your choosing. We like to let
ours dry out and have fairly hard pieces of candied ginger, but you can
move to an airtight container sooner rather than later and the ginger
will stay moist.

Ginger syrup is lovely in tea, we find, as well as useful for homemade
ginger soda.

=S=