1. Cut a small, shallow "x" in the bottom of each peach.
2. Blanch peaches in a large pot of boiling water until skin loosens, 1-2 minutes. Place peaches in a colander and run cold water over them.
3. Peel the peaches and cut the flesh away from the pits. Combine with sugar, lemon juice, and anise hyssop flowers in a large bowl and allow to stand for 30 minutes. Add the calcium water and the pectin.
4. Transfer fruit mixture to a large heavy pot. Bring to a boil, then reduce heat to low-medium, and cook for about 20 minutes. Stir briskly to dissolve the pectin at first, then stir every now and then until the jam reduces and thickens.
5. Skim any foam from the surface of jam, then ladle into sterile 1/2 pint jars. Wipe rims, seal, and process in a boiling water bath for 10 minutes.