Remove any stems / leaves from the fruit and wash. Cut fruit in half the long way and remove any seed and as much of the big white pith running lengthwise. Don’t get crazy about that. Just get out as much as possible. Then cut the fruit, peel and all into lengthwise very thin strips. Pull out any seeds you encounter. You should have about 4 cups of cut fruit when done.
Place in a 6 – 8 qt pot with about a cup of water. Zest the lemons and add the zest and juice to the pot. Cook over medium heat until almost boiling. Simmer for about 5 minutes. Measure what you have. You should have between 4 and 5 cups of fruit / liquid.
Measure out your sugar now and have it ready. Put the fruit back in the pot. Add the half package of pectin. Bring the mixture to a full rolling boil – a boil that doesn’t stop bubbling when stirred) on high heat, stirring constantly. Add the whole batch of sugar and keep stirring on high heat. Return to a full rolling boil and boil exactly 4 minutes. Turn off heat and skim any foam with a metal spoon.
Ladle into prepared jars, filling to within 1/8 inch of tops. Wipe jar rims and threads. Cover with two-piece lids. Screw bands tightly. Place jars into canner. (Water must cover jars by 1 to 2 inches; add boiling water, if necessary.) Cover; bring water to gentle boil. Process 10 min. Remove jars and place upright on towel to cool completely.
After jars cool, check seals by pressing middles of lids with finger. (If lids spring back, lids are not sealed and refrigeration is necessary.) While processed jars are cooling, shake jars GENTLY once or twice to evenly distribute the fruit. You may still find that much of the rind ends up at the top of the jar.