How to Make Liquid Hand Soap from Bar Soap - from The Farmer's Nest. Great money saving idea! Here's what you need: -Cheese grater (from the dollar store) -2 Tablespoons of Liquid Glycerin (found in the band aid section at any drugstore or grocery store) -1 - 8 oz bar of soap -1 gallon of water. Step 1: Grate the entire bar of soap. Step 2: Fill a pot with 1 gallon of water and add the soap shavings. Step 3: Add 2 Tablespoons of liquid glycerin and turn the heat to medium/high and stir until the soap dissolves. Step 4: This is what it looks like once it's dissolved, basically just soapy water. Step 5: Leave it alone to cool for at least 10-12 hours. It begins to cloud up after 3-4 hours. Step 6: After it has cooled completely around 12 hours later it will harden and look like liquid soap. Step 7: If the soap is harder than it should be you can take some beaters and blend it while adding just a little bit of water until the consistency is more like liquid soap.