Wash berries and put in large kettle with the one cup of water. Bring to almost a boil, cover kettle and simmer until berries are real tender stirring often to prevent any sticking. After berries are tender mash thoroughly through a fruit sieve to remove seeds. (This is tedious but you want as much of the pulp as necessary.to make 6 cups of mashed fruit.) Discard seeds.
You might have to wash the kettle out as you don't want any seeds or little stems in your jam. Add the lemon juice and powdered pectin to the mashed fruit and bring rapidly to a boil that can't be stirred down. Stir constantly to prevent sticking or scorching.
Add the 8 1/2 cups of sugar gradually to prevent lumps and keep stirring constantly until all sugar is dissolved.
Bring this mixture to a boil that can't be stirred down over high heat and start timing and stirring constantly for 2 minutes. When two minutes are up, take the pot off the heat and let set a few minutes for the foam to settle. Skim foam and save for eating later as it's good too.
Pour hot jam into sterilized 1/2 pint jars to within 1/4" of top. Seal with sterlized lids and rings and process in boiling water bath 5 minutes. I got 8 1/2 half pint jars of good jam without the foam, but another pint jar of foam/jelly. The recipe should make 9 1/2 pint jars of jelly but loss was due to the thick foam the jam made.
I've heard that adding a little margarine to the mixture helps reduce foam but it will alter the taste of the jam somewhat.
All in all, the 8 jars of jam are really good tasting and a nice dark brick colored red.
Bonnie in TN