For the berries:
Bike to the Albany bulb on a sunny afternoon in August. Walk out near the end of the peninsula, turn right at the path that aims toward the two red-and-white radio towers, and walk down to the water. You will see bunch of art and a bunch of wild blackberry bushes. Pick about 3 quarts of berries and bike back home.
Rinse the berries thoroughly in a colander, spread them out on baking sheets, and pick out any tiny ants and tiny inchworms that you see crawling around (there will only be a couple of each, not bad at all). Put the sturdiest quart-worth of berries in tupperwares in the freezer; use the squishiest, ugliest 3 cups of berries for jam as described next; and put the rest of the berries in the fridge for tomorrow.
For about 1.5 c jam:
3 c blackberries
1 T lemon juice
1 T minced lemon peel (reserved from limoncello)
1.25 c sugar
Choose your jam jars, and clean and/or sterilize them as you see fit. I simply filled my clean jar with boiling water and let the lid sit in a bowl of boiled water while I cooked the jam.
For a seed-rich jam, put the berries in a large pot and crush them with a potato masher. For a seed-light jam (my preference), put the berries in a colander over a large pot, crush them with a potato masher to get as much juice out as you can, then squish even more juice out by pressing down on the remaining solids with the base of an appropriately-sized bowl. I ended up with about 2 c of juice (plus some seeds that slipped though) in the pot.
Either way, stir the lemon juice and peel and the sugar into the berries. Cook over medium heat, stirring almost continuously, for about 20 minutes or until the temperature reaches 222F; the jam should be obviously starting to jell. Carefully transfer the jam into jars, screw the lids on tight, and let cool on the counter overnight. Eat on biscuits for breakfast and store in the fridge.