First we have the five elements water, fire, wood, metal and earth. Water moistens downwards. Fire heats upwards. Wood is both crooked and straight. Metal can be changed into various shapes.
Earth is for planting crops.
Moistening downwards makes the salty taste. Heating upwards makes the bitter taste. Crookedness and straightness make the sour taste. Changing into shapes makes the pungent taste. Crops make the sweet taste.1 Chinese civilization was born with agriculture.