Alexandra G. McMahon, B.S., Research & Development Chemist, Koster Kuenen, Inc.
Belen M. Lemieux, M.S., Research & Development Laboratory Manager, Koster Keunen, Inc., lemieux@kosterkeunen.com

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Abstract

Humans have been manufacturing soap since at least 2800 B.C., modifying and perfecting their recipes over the centuries. Today’s traditional soap bars are made via saponification of triglycerides: the alkaline hydrolysis of fatty ester bonds, leading to mainly C16-C18 fatty acid soaps and glycerol. In this paper, we explore the use of Natural Waxes from Koster Keunen, Inc. as starting raw materials in soap formulations, both alone and as additives to traditional triglycerides. Twelve Natural Waxes were blended with olive oil at 50/50 ratios, each blend was fully saponified, and the reaction products were evaluated for different properties and compared to a standard olive oil soap bar. It was determined through experimentation that each Saponified Natural Wax or Saponified Natural Wax Blend made a chemically complex finished soap, with different properties from the control and from each other. Some of the benefits encountered included improved bar hardness, a longer lifespan, more hydrophobicity, and innovative INCI declarations. 

Introduction and Background

Few personal care products can have their history traced as far back as soap. While the historical accounts on soap and soapmaking are rife with legend, experts agree that the earliest evidence dates back to 2800 BC in Ancient Babylon, when a soap-like substance was discovered during an archaeological dig¹.

Other records show ancient Egyptians, Greeks and Romans also made and used soap for thousands of years, perfecting the technique over time. By 1100 AD, soap making was an established practice in Mediterranean countries with easy access to olive oil, a key ingredient in Castille Soap, which was widely traded at the time².

Soap was introduced to the Americas in the 17^th century, when soap makers arrived in Jamestown, VA¹. Over the next 200 years, as the United States industrialized, soapmaking evolved into one of the fastest growing businesses, with P&G’s Ivory being one of the first to gain national distribution³. However, food and fat shortages during World War I led German engineers to introduce synthetic replacements for soap, now known as detergents⁴. American consumers quickly embraced detergents due to their efficiency, availability, and low price; moving traditional soaps over time to niche market segments, particularly “Indie” brands, artisanal soap makers, and crafters⁵.

In recent years, and specifically at the onset of the COVID-19 Pandemic, the demand for hand soap has escalated. In fact, the global hand soap market is forecasted to grow by 6.7% from 2020 to 2030, with the household segment accounting for over 70% of the market share⁶. Although it is not clear what percentage of said growth refers to traditional soap bars (versus “syndet” bars or liquid detergents), current consumer trends, such as natural ingredient demand, small business support, and plastic reduction seem to support the persistence of traditional soaps^{7, 8}.

Soap Chemistry and The Role […]