When you DIY your homemade liquid soap, you can control the thickness by adding simple ingredients call HEC – Hydroxyethyl cellulose. Hydroxyethyl Cellulose (HEC) is a natural gum derived from pine and spruce tree trunks. It is a non-ionic, water soluble thickening agent for water based cosmetic and personal care products. Hydroxyethyl Cellulose will also help…