Why SugarThick didn't thicken kaffir lime fermented water

Based on the information provided, SugarThick (PEG-120 Methyl Glucose Dioleate) is a non-ionic thickener commonly used in surfactant-based systems like shampoos, body washes, and cleansers. It works by associating with surfactant micelles to build viscosity.

Your formulation consists primarily of fermented water (95%) and SugarThick (5%). Fermented water, especially from natural sources like kaffir lime, typically does not contain the necessary surfactants that SugarThick requires to create viscosity. Heating to 50-60°C helps dissolve the SugarThick, but it does not change its fundamental mechanism of action, which relies on the presence of surfactants.

Therefore, the reason your mixture did not thicken is likely due to the absence of surfactants in the kaffir lime fermented water. SugarThick is not effective at thickening simple aqueous solutions or solutions without a significant surfactant phase.

If you wish to thicken the fermented water, you would need to use a different type of thickener that works in simple aqueous or potentially acidic systems, such as certain types of gums or polymers. If your goal is to create a product that also cleanses, you would need to add surfactants to the formulation, and then SugarThick would be effective.