Cut the grapefruits in half.

Using a citrus juicer or reamer, squeeze the juice from each half into a measuring cup.

Taste the juice. If it's too tart, stir in sugar one tablespoon at a time until desired sweetness is reached.

If preferred, strain the mixture through a fine mesh strainer into a pitcher.

If the juice is too strong, add a bit of water to achieve desired strength.

Chill the juice in the refrigerator for about 30 minutes.

Pour the chilled juice into glasses and garnish if desired.

Serve and enjoy your homemade grapefruit juice.