A method of manufacturing a porous vegetable filler for use in a foaming process mainly comprises exposing discarded coffee grounds to sunlight to a moisture content of 5%-15% then baking the coffee grounds after solarization using a dryer at 120° C.-350° C. for 1 to 4 hours finally grinding the baked coffee grounds to a size of less than 1000 mesh to obtain a porous vegetable filler for use in a foaming process.
