An oil-in-water emulsion useful as a defoamer for pulp and paper mill applications is described. The defoamer has an oil blend (of a triglyceride oil or a mixture of triglyceride oils and silicone), a stabilizing agent (to make the oil blend stable in the emulsion), hydrophobic silica particles, surfactants, dispersants, and other components. The emulsion is usable directly at low concentrations to control foam.