Tip the coffee into a large ceramic or glass jug. Add the water, stir well and cover. Stir again after one hour, then leave on the work surface or in the fridge for 12-24 hours.
Place a sieve over a bowl that will hold at least 1 litre. Line with a piece of cheese cloth, an old clean tea towel or a coffee filter. Pour the coffee through the sieve to remove the coffee grounds. Sieve again using a clean cheese cloth etc if necessary.
Store in the fridge for up to one week.
Dilute to taste with water or milk adding sugar or agave if you wish.
*Anything ground for a cafetiere (French press) will be great