The mechanism of how soy adhesives work in wood composites is becoming clear based on the spectroscopic and physical property research that has been conducted. The data shows that the adhesion mechanism of soy adhesive to wood, crosslinked with polyamideamine-epichlorohydrin (PAE), is dominated by the viscoelastic behavior of the adhesive and that there is some chemical crosslinking. The penetration of the water-soluble components from soy into the wood is a major part of the adhesion mechanism. We have identified some of the water-soluble components that contribute to the poor moisture resistance of soy adhesives and are exploring chemistries that would react with these water soluble moieties and render them more stable and resistant to washing out of the adhesive.