How to Make Jelly
Jellies are made from fruit juice and sugar cooked together until the jelling point is reached.
In addition to your large kettle and long-handled spoon, you will need a jelly bag made of cheesecloth or flannel (nap side in), a rack or colander to hold the bag, and a large bowl to catch the juice. Do not squeeze the bag when straining juice for jelly or your finished product will be clouded. You will also need a ladle to fill the glasses.
To extract the juice from fruit, cover apples and other hard fruits with water and boil for 20 to 25 minutes; crush berries or grapes. Add only enough cold water to prevent burning and cook about 10 minutes. Do not overcook or the flavor and pectin content will suffer.
After the juice has been extracted, return it to the pot with sugar and cooked over moderate heat until the sugar dissolves. Then raise the heat and boil rapidly until the jelling point (220°F at sea level) is reached.