Prepare 4 half pint or 8 1/4 pint jars.
In a saucepan, combine sugar, salt and vinegar.
Bring to a boil over medium high heat, stirring often until sugar and salt are dissolved.
Add horseradish and return to a boil, stirring occasionally to immerse horseradish in liquid. Remove from heat.
Pack hot horseradish and liquid into hot jars, leaving 1/2 inch headspace by adding the hot liquid. Remove air bubbles and adjust headspace as necessary. Wipe rim and add hot lid and rings. Tighten finger tight.
Place jars in water bath canner and return water to a boil. Process for 10 minutes. Remove jars and set on dishtowel overnight. Check lids the next day and refrigerate any jars that have not sealed or reprocess the jars again.
Horseradish root should be firm. You will need 3lbs of whole root to get 7 cups of shredded horseradish.