If fruit is organic and has no waxy coating, rinse with cool water and scrub fruit lightly with a brush. If it has a waxy coating rinse with boiling water first then cool water and scrub.
Remove zest from lemons with a vegetable peeler with as little white pith as possible. Slice into thin strips and place in a medium saucepan.
Peel the pith off of the lemons and discard. Roughly chop the lemon pulp, discard any seeds. Add pulp to the lemon zest in the saucepan.
Add the water to the saucepan. Bring to a boil, reduce heat and let simmer for 5 minutes. Pour into a non-metal bowl, add rosemary stalks.
Cover and let sit for 12-18 hours. This is essential! The lemon juice will soften the lemon zest during this process. Otherwise it will harden an be inedible once the jam is cooked.
Place 3 or 4 metal spoons in the freezer about 1 hour before cooking. Sterilize canning jars.
Remove rosemary stalks. Measure the fruit and liquid and pour into a large pot. Add 1 cup of sugar for every cup of mixture.
Bring to a boil over high heat, stirring constantly. Continue cooking as mixture thickens.
To test for gelling point, pour a small amount of marmalade onto one of the frozen spoons to cool quickly. Pour off of the spoon, if it is thin and syrupy keep cooking. It is done when the cooled marmalade pours off in a sheet or clump.
Add to jars and process in a boiling water canner for 10 minutes for half pint jars (aka 1 cup jelly jars).
Notes
For more information on water bath canning refer to Fresh Preserving.