An adhesive mixture comprising an organic slurry dispersion for use in the manufacture of wood-based composites is described herein. The adhesive mixture includes an adhesive resin; water; one or more fillers, and an organic slurry dispersion. The organic slurry dispersion includes water; a natural biopolymer insoluble in the water, the natural biopolymer comprising lignocelluloses, lignocellulosic agricultural residue, lignin materials, lignin derivatives or mixtures thereof; and a defoamer. During manufacturing, the components of the organic slurry dispersion are combined and mixed by imparting a high degree of shear and mixing. The adhesive mixture may be applied to wood material for use in manufacturing a wood-based composite product.