Water is half the cup

Very hard water binds the acidity in coffee. The cup tastes flat and a little chalky, however good the bean. Very soft water, on the other hand, quickly makes it sharp and sour.

Try it: brew once with tap water, once with a still water low in minerals. Same bean, same grinder, same timer. The difference surprises almost everyone.

Our timer works with water in grams, not millilitres. A scale under the kettle is the second best tool after good water.