Truffles, soil & trees
Truffles usually grow under Oaks, Poplars, Willows, Kernels and Lime trees. The characteristics of the trees inform those of the truffle to determine the colour, the flavour and aroma. For example, truffles that grow near oak trees have a fuller, woodier scent, while those near the lime trees are more fragrant and aromatic.
Truffles are mainly made up of water and minerals absorbed from the soil through the roots of the trees with which they live in symbiosis. After it is formed from the spore, the truffle absorbs the sap which the roots of its host plant take from the earth. The shape they will become depends on the type of soil: if it is soft, truffles will tend to be smooth and rounded whilst compact clay soils produce more gnarled and lumpy types, as they expend more effort to find room for growth in the soil.