50g ground coffee (use coarsely ground for cafetières)
sparkling water or still water to dilute
Put 400ml cold water into a large jug or jar and add the coffee grounds, but do not stir the mixture. Cover and leave to steep for 24hrs.
Gently stir the mixture then pour it through a funnel or sieve lined with coffee filter paper (or a sheet of kitchen paper) into another large jug. This concentrate will keep in the fridge for 2-3 days.
To serve dilute 1 part cold brew with 2 parts still or sparkling water (or to your taste) and serve with lots of ice.