1.⁠ ⁠Peel and roughly chop the ginger and turmeric.
2.⁠ ⁠Add them to a pot with water and gently simmer for 15–20 minutes.
3.⁠ ⁠Let the mixture cool slightly, then blend until smooth.
4.⁠ ⁠Strain if desired and add freshly squeezed lemon juice.
5.⁠ ⁠Add a pinch of black pepper to activate the turmeric.
6.⁠ ⁠Pour the liquid into ice cube trays and freeze.

Once frozen, store the cubes in an airtight container in the freezer.