Ours is not sour at all and I'm pretty sensitive to sour stuff. 700 ml water, 50-60 g beans, 24 hours in fridge. When drinking we mix with 3-4 parts water. I a

Ours is not sour at all and I'm pretty sensitive to sour stuff. 700 ml water, 50-60 g beans, 24 hours in fridge. When drinking we mix with 3-4 parts water. I always drink cold, wife drinks it hot. Lots of flavour and fun to try the local roasterys seasonal tastes.