This new formula of Fels-naptha is very easy to cut with a knife. It still needs to be diced much smaller than this, before adding to the pot of simmering hot water. Most Laundry Soap recipes call for using a kitchen grater, but I can't see any need for that, unless you want to do it that way. I better store the bars in an airtight container, in case they harden with age though.