Detergents and Soaps

What's the Difference?

Because water is not very good at removing dirt and grease by itself, most people add soap or detergent to help clean their clothes, dishes, or their skin. Detergents are synthetic formulations that were created to mimic how soap cleans.

There seem to have been two main reasons that led to the development of detergents. First, there was a shortage of animal and vegetable fats (natural soapmaking ingredients) during the world wars. Researchers created detergents using petroleum, as a substitute for soap. And second, when soap alone is used in washing machines, hard water can cause precipitates to form, which leaves a build up on the machine. Detergents use extra chemicals to make them less likely to be affected by the presence of minerals in hard water.

So although detergents and soaps clean in the same manner, they are created differently. Soapmaking combines fats and oils that are plant or animal based with an alkali (lye) to produce soap in a process called saponification. Detergents are primarily petrochemical (crude oil) and sulfuric acid based surfactants.

A surfactant (“surface acting agent”) is anything that lowers the surface tension of water. This allows the water to clean better because it doesn’t stick to itself (like a drop of water staying bubbled up on a table). Instead, the water spreads out so it can more easily interact with the oil and grease and ultimately wash it away. Detergents and soaps are both surfactants.

To improve performance, most modern detergents also have additional chemicals added, such as:

- Enzymes to break down protein-based stains.
- Bleaches (e.g. sodium perborate) to remove the color from stains and boost cleaning properties.
- Optical Brighteners to offset the natural yellowing.
- Antiredepositation agents to prevent soil from settling back on washed clothes.
- Processing aids (e.g. sodium sulfate) to prevent caking of the detergent itself.
- Perfumes to cover the smell of the detergent itself.
- Suds control agents to reduce the suds produced during washing (typically for high efficiency washing machines)
- Corrosion inhibitors (e.g. sodium silicate) to prevent washing machine damage.

So while detergents and soaps clean in the same manner, they are made with very different ingredients. Sales of detergents exceeded soap sales in the United States in the 1950’s. But with the “green movement” we may see this reverse due to all the chemicals present in detergents.

At Goat Milk Stuff, we don't like to use detergents on our clothing or our skin. Our laundry soap is just that - soap. Not detergent. And once you feel the difference our goat milk soap makes on your skin, you won't want to use detergents ever again!