Even if you don't have crystallised ginger on hand, you can reap this rhizome's sweet and spicy rewards in your cooking. The crystallisation process emphasises ginger's sweetness while muting its spiciness, so crystallised ginger is used mostly in recipes for candy-making or baking, or as a gummy, sweet snack eaten on its own. Raw ginger's spiciness can be overpowering, however, and it is too tough to bite into easily. Though the crystallised and fresh versions of the ginger root have extremely different tastes and textures, it is sometimes possible to substitute fresh for crystallised, or to crystallise fresh ginger root at home.
Cut a peeled ginger root into one-inch pieces to measure it; 1 square inch of the fresh root is about equivalent to 1 tablespoon of it minced. One tablespoon of minced fresh is roughly equivalent to 1/4 cup minced crystallised ginger.
Grate the raw ginger until you have the amount equivalent to the amount of crystallised ginger your recipe requires.
Mix the freshly grated, raw ginger with an equal amount of granulated sugar. Add the mixture directly to the dish's batter. A coarse version of crystallisation will occur within the dish as it bakes.
Crystallise the fresh ginger if you're substituting in dishes that are uncooked or making stand-alone candy. Any food preparation that leaves you biting into the ginger directly requires the crystallised form for the desired sweetness and to keep from the ginger's spiciness from overwhelming the dish.
Place the peeled and sliced or cut ginger in a saucepan, to begin the crystallisation process. Cover the ginger pieces with water and simmer until they're soft (30 minutes to one hour). Drain.
Put the ginger back in the saucepan with an equal amount of sugar, plus 2 to 3 tbsp of water. Stir often and bring to a boil.
Reduce heat and stir constantly until all liquid evaporates and the ginger pieces start bunching together.
Let the ginger pieces cool slightly, then either roll them on a cookie-sheet covered in sugar, or toss them in a sugar-filled zip-up plastic bag.
Fresh ginger can be very difficult to chop or peel because the root is so knobby and run through with fibres. It is usually easiest to steam the root for 30 seconds to 1 minute in the microwave (put the root in a bowl with a few tablespoons of water, and cover it with a paper towel), or to use a ginger grater. Slice off any especially knobby roots, instead of attempting to peel them. To substitute crystallised ginger for fresh, wash off its sugar coating first. Crystallised ginger lasts for three to six months stored in an airtight container, in a cool place.