Strip the currants from their stems. Place in a ceramic or glass bowl and crush with a potato masher. Transfer the fruit and every drop of juice to a quart Mason jar and add the Everclear. Seal the jar, and leave it in a cool, dark place for a week or two. Agitate the jar every other day.
Strain the contents of the jar through a damp jelly bag, and squeeze out as much liquid as possible. Put the liquid in a saucepan with the water and sugar. Heat over medium heat, stirring constantly, just until the sugar dissolves. Ladle the hot liqueur into scaled bottles. Seal with a cork or stopper. Age at least 6 months in a cool, dry place.