The one with ginger powder, yeast and sugar is for ginger beer. Good stuff, but not the same as cordial I think. We used to keep a ginger beer "plant" in a jar. Consisted of ground ginger, yeast and water. You feed it every day for a week with a teaspoonful of ginger and a teaspoon of sugar. After a week you strain it through muslin, and add lemon juice and water to the liquid. Can't remember the quantities. The sludge left in the muslin is divided in half, give one half away and put your half back into a jar with water and continue as above. The result is alcoholic, but not too strong. Anyone got the proper recipe?