100 ml heavy simple syrup (2 parts sugar to 1 part water)
1 tsp lemon extract - add to syrup after it is cooked
Put currants in small crock pot with enough water to cover. Cook, covered, for one hour on high, two hours on low. Let sit for at least one hour to cool. When currants are cool enough to handle comfortably, strain to remove solids. I used a cold coffee extraction rig lined with a fine mesh nylon straining bag made for brewing. When the bulk of the liquid had drained out, I wrung the bag to force out any remaining - this is the point where a nylon straining bag is critical, you don’t want the seams blowing out. I then combined the rum, lemon syrup, and currant juice in a large glass container and let it sit for a week before drinking.