A slurry product is packaged into a plastic bag using a modified form-fill-seal apparatus. A method for making a plastic bag filled with a desired weight of a slurry material on a form/fill/seal machine, includes drawing a plastic film over a mandrel of a form/fill/seal machine and wrapping the film around a forming tube. A tube of plastic film is formed by bonding the edges of the film together and the bottom of the tube is sealed. An initial weight is obtained by weighing the mandrel and the tube of plastic film then a slurry composition is deposited inside the closed tube. The present weight of the mandrel, tube of plastic film and contents of the tube are monitored as the slurry is deposited, and the present weight and the initial weight are compared until a desired weight is reached. After the desired weight is reached, the filled bag is sealed and separated from the tube of plastic film.