Cut the pomegranates in half. Submerge a half in a large bowl filled with tap water. Carefully remove the seeds underwater. Separate the white membranes from the seeds. Discard the skins and membranes. Repeat with the rest of the pomegranates.

Dry the seeds with paper towels. Place the seeds in a blender. Pulse the blender a few times to break the seeds. Place a mesh strainer over a bowl. Place a paper towel or cheesecloth on top of the strainer. Pour the pomegranate juice into the paper towel or cheesecloth. Squeeze and extract all the juice out from the seeds.

In a small saucepan over medium heat, add 1-cup pomegranate juice, sugar and lemon juice. Cook until the sugar has dissolved, stirring occasionally. When the sugar has dissolved, reduce heat to medium-low and cook until the syrup has reduced to 1/3 cup, about 45 minutes, stirring occasionally. The syrup should be dark and slightly thick. It would get thicker when cool. Remove from heat and let it cool for 30 minutes. Transfer to an airtight container. Let it cool completely before placing in the fridge.