Abstract: A method for extraction and isolation of proanthocyanidins from biological material. The method includes the steps of hot water extraction of the material after comminution using deoxygenated water, separation of the solids from the liquor, concentration of liquor into a concentrated solution and waste streams,and drying the concentrated solution to a solid product. The hot water can be recycled. The residue results in a usable by-product and the tannins can be extracted from the tannin-rich waste stream. The most preferred biological material is bark from Pinus radiata trees which are 15 years old, the bark most optionally coming from the upper portion of the tree.