Place the currants into a large pot, and crush with a potato masher or berry crusher if you have one. Pour in 1 cup of water, and bring to a boil. Simmer for 10 minutes. Strain the fruit through a jelly cloth or cheese cloth, and measure out 5 cups of the juice.
Pour the juice into a large saucepan, and stir in the sugar. Bring to a rapid boil over high heat, and stir in the liquid pectin immediately. Return to a full rolling boil, and allow to boil for 30 seconds.
Remove from heat and skim off foam from the top. Ladle or pour into sterile 1/2 pint jars, filling to within 1/2 inch of the top. Wipe the rims with a clean damp cloth. Cover with new sterile lids and rings. Process in a hot water bath for 10 minutes or the time recommended by your local extension for your area.