I have a row of six Redcurrant bushes at the end of my vegetable garden. I picked up red currant fruits yesterday and made the jelly. The crop this year was excellent. I filled up a bucket full of redcurrant (10 L) for jelly and left some fruits to eat as well.
Firstly, wash up the fruits and remove leaves and stalks.
Then, put the fruits in a pot and get warm. Do not boil, you will destroy the natural pectin molecules that actually make the jelly hard. I use to crush the fruit with hand mixer and mash it (maybe you have the mashing machine or you can do the same by passing the fruit through the clean piece of gauze).
Put it on fire again and add some pectin powder (read the instructions on the bag) and add sugar. The Redcurrant is sour a bit so you can add 0.6 to 1 kg of sugar to one kilo of mashed fruit. Do not boil! Stir regularly until sugar dissolves.
Remove the foam as it forms. You don't have to throw it away it is good to eat too. Wash the jars and warm them up in a oven. Fill with jelly and close immediately.
I got six large and three small jars of red currant jelly.