Peel the grapefruits and remove as much white pith as possible to reduce bitterness. Hull the strawberries.
Juicer method: run the grapefruit segments and strawberries through a juicer.
Blender method: squeeze the grapefruit, then blend the juice with the strawberries until smooth. Strain through a fine sieve if you prefer a thinner juice.
Taste and stir in honey or maple syrup if needed.
Pour over ice and serve immediately.
Notes
Best served fresh. Store in a sealed jar in the fridge for up to 24 hours and stir before drinking. Use maple syrup to keep it vegan.