Puree the onion and vinegar together in a blender until smooth. Pour into a saucepan. Add the sugar and crushed pepper and bring to boil over medium-high heat. Boil for five (5) minutes and then stir in the powdered pectin. Bring to a hard boil and boil for one (1) minute. Pour into hot sterilized jars, secure the lids and process for ten (10) minutes in a boiling water bath.