Set out 4 garlic cloves, 12 Thai chillies, 2 cups blueberries, 1½ tbsp sugar, ¼ cup vinegar.
Crush garlic cloves. Trim chilli stalks, leaving green top intact. Chop roughly.
Place thawed blueberries and chopped chillies in the jug of a blender.
Add garlic, sugar, 1 tsp sea salt and ¼ cup filtered water to the blender.
Blitz into a rough paste. Taste for heat and add more chilli for a spicier sauce.
Pour into a jar. Cover with cheesecloth. Ferment at room temperature for 3-5 days.
Stir daily with a clean spoon. Keep out of direct sunlight. Once bubbles subside, it’s ready.
Pour sauce and vinegar into the jug of a blender and process until smooth.
Strain through a sieve and decant into a clean 500ml bottle. Chill for up to 4 weeks.