First phase:

• Pour 750ml of the alcohol into a jar with a good seal (e.g. a mason jar).
• Grate the zest and add it to the alcohol, being very careful not to add any of the white pith.
• Cover the jar with aluminium foil. Place it in a dry, dark place and leave it undisturbed for 45 days.
• Second phase:
• Put the water and sugar in a pot and heat, stirring until the sugar has dissolved.
• Let the sugar syrup cool, then add it to the lemon mixture from the first phase, along with the last 250ml of pure alcohol. Stir.
• Cover the jar in foil, and put in a cool, dry place for at least 40 more days.
• Third (and last!) phase:
• Pour the limoncello through a fine-meshed sieve to strain out all the bits of lemon zest.
• Put it into clean glass bottles with good caps or seals.
• Put it in the freezer, wait for a few hours and then, DRINK (though try not to drink it all at once)!