First, prepare lids, jars, and a water bath canner.
Wash, drain, and destem your currants. If frozen, thaw in a colander, placing a bowl below to collect the juice.
Bring a few quarts to a boil so you can blanch the berries. Working in batches, add the currants to boiling water and boil for one minute. Remove and place in a covered pot or bowl to keep warm.
Next, combine Clear Jel and sugar in a large pot. Add the cold water (or chilled juice and water) to this mixture and whisk to dissolve. You must completely dissolve the Clear Jel before moving to the next step.
Once dissolved, heat on medium-high heat, whisking or stirring continually as the mixture thickens. Once bubbling, add the lemon juice and cook for an additional minute.
Remove from heat and fold in your drained, blanched currants.
Immediately ladle into prepared canning jars, being sure to de-bubble the thick mixture and allow 1 inch headspace.
Clean the rims of any lingering residue and apply 2-part canning lids.
Process in a water bath canner for 30 minutes, adjusting for altitude.
Once the full processing time has passed, turn off the heat and allow jars to sit for another 10 minutes in the water bath canner. This will reduce the chance of siphoning.
Remove with a jar lifter, placing on a towel to cool. Allow to rest 12 to 24 hours before checking the seals. Move any unsealed jars to the refrigerator for immediate use.
Jars of currant pie filling that are properly stored and sealed will maintain peak quality for 12 months. Refrigerate after opening.