In a saucepan, combine pomegranate juice, sugar (or sweetener), and freshly squeezed lemon juice.

Stir over medium heat until the sugar fully dissolves.

Bring the mixture to a gentle simmer, then reduce the heat to low and simmer for 10-15 minutes to thicken.

Allow the grenadine to cool to room temperature.

Strain the syrup to remove any pulp.

Optionally, add a tablespoon of vodka to extend the shelf life.

Transfer the grenadine to a clean, airtight bottle and store in the refrigerator.