Freshly picked washed mushrooms are subjected to a modified atmosphere and infused with a suspension containing a particulate microscopic heat-stable, gel-forming material. The method includes the steps of: introducing the mushrooms into a sealable container containing a water suspension of a heat-stable, gel-forming material in the form of a particulate colloidal suspension therein, the average particle size being less than 2 microns; subjecting the contents of the container to at least one application of a pressure and submerging the mushrooms in the water suspension while restoring the pressure in the container to atmospheric pressure; and removing the mushrooms from the container, thereby infusing the heat stable, gel-forming material in the form of the particulate colloidal suspension into the mushrooms. Upon blanching in boiling water, the weight loss experienced is reduced from a normal 25% to 33% loss to between a 2% loss and a 5% or more weight gain. The resulting mushrooms, in addition to the reduct
