Remove the stem from the strawberries and halve or quarter them if they are large. Place them in a large stockpot with the water and bring to a boil. Cover, reduce heat to medium and continue to boil for 10 minutes, stirring occasionally to prevent the berries from sticking to the pot.

Meanwhile, put the sugar and basil leaves into a food processor fitted with a steel-blade attachment. Pulse until the basil is finely minced and the sugar turns a pale green color. Set aside.

Remove the lid from the pot and stir the lemon juice into the berries (after they have simmered for 10 minutes). Add the sugar, ½ cup at a time, waiting for the liquid to return to a boil before adding more. Continue to boil for another 5 minutes, stirring frequently. Skim any foam that rises to the surface, if desired. Cook only until the jam begins to stick on the bottom of the pot. You should be able to draw a trail through the jam with your spatula. Another sign that the jam is ready is that it will begin to sputter.

Pour jam through a funnel into hot, sterilized jars to within ¼ inch of the lips. Wipe the rims clean with a paper towel that you've submerged in the vodka. Attach new lids, and screw caps tightly. Invert jars briefly to vacuum seal, or process in a boiling water bath, submerged by 1 inch, for 10 minutes.