The purpose of binders is to help bind the meat together and retain juices. Really only needed in smoked and cooked sausages. Helps maintain plump sausage and prevent drying. Almost certainly all premixed seasonings contain a binder of some sort, either nonfat dry milk, or soy protein concentrate. Either one is generally used at a rate of 12 oz. per 25# of meat. Butcher Packer, Allied Kenco, The Sausage Maker, or Midwestern Research are all good sources. I have successfully used regular store bought powdered non fat dry milk with good results too, I just give it a whirl in the food processor so it is more of a powder than the flakes it comes as.