Soap Basics

Handmade Soap

Handmade Soap

By Cat, May 2008 (Photo, right, from Wikimedia Commons); 2018 Update: Making Real Soap at Home moved to it’s own page; 2020 Update: regarding Coronavirus-COVID-19

In the not too distant past, homemakers routinely made their own cleaning and personal care products from ingredients in their own kitchens. As fuel costs rise and petroleum-based products become more scarce and expensive, we may once again return to the much more healthful practice of making our own, and it’s better for the environment too.

When I was growing up in my rural Montana town in the 1950s, many of the town families saved used lard and bacon fat in our kitchens for use by the local farm housewives for making kitchen and laundry soap. These same housewives also made more delicate soaps and lotions for personal care.

Real Soap

One of the disgusting, and environmentally harmful things brought to us by the 20th century is detergent. I’m talking laundry detergent, dishwasher detergent, liquid dish detergent, and liquid shampoos. In older times, people used soap, and the cream of the crop is known as Castile soap. Most bar soaps are real soap – especially those that are handmade (at your or someone else’s home). But beware with liquid “soaps,” as most contain detergents (which are made from petroleum).

Oh yes, detergent is one heck of a grease-cutter. But it also has toxicity issues for you and for the environment. Plus, it does not have innate anti-microbial ability provided by real soap. If you want anti-bacterial coverage with detergent, you need to buy products that include a synthetic antibacterial additive (such as triclosan), or buy a synthetic hand sanitizer separately [NOTE: these kill both the good and the bad bugs]. Widespread use of these antibiotic agents is helping to increase the number of antibiotic-resistant bacteria like MRSA. Plus, they don’t protect you from disease-causing viruses or fungi (real soap does provide this protection)

What’s the difference you ask?

Soap vs Detergent

How are soaps protective of skin health, while detergents are detrimental to skin health?

Your skin has its own microbiome that protects the skin and works in symbiotic fashion with the skin cells. This microbiome is affected differently by soaps vs detergents:


  • Soaps are naturally anti-microbial when mixed with water, in that they pull the microbes  – good and bad – away from the skin, and the water removes them, down the drain. Good microbes in the air return to the skin, to protect it from invasion by bad microbes. But soaps have other anti-microbial abilities too, in that their chemical make-up actually makes it hard for bad bugs to exist in soap’s presence.
  • Real soap has made headlines lately (2020 update) with the emergence of the new coronavirus, COVID-19, because of real soap’s ability to kill not only bad bacteria but also bad viruses; see Mercola’s article: 6 Tips to Help Protect You from the Coronavirus [9d]. Note that real soap does NOT kill good bacteria/viruses – only the bad ones. How does it kill viruses? 
  • Soap “dissolves the fatty membrane that holds the virus together. As the virus falls apart, it is rendered harmless and can easily be washed off under running water.” (9e)


  • Detergents on the other hand, do NOT kill the bad bugs on their own.
  • They typically contain anti-microbial chemicals such as triclosan, which kill all microbes, good and bad. These chemicals are not easily rinsed away and continue to kill the good microbes as well as the bad, depriving the skin of it’s important partner, the good bugs.

The Science

Several scientific studies have been done that show the amazing ability of real soap to  keep bad bugs at bay. The one that impresses me the most was done in 1965 (this summary is from Mercola, (9a).

“Researchers intentionally contaminated their hands with nearly 5 billion bacteria [9b], including disease-causing strains such as staphylococcus and E. coli. They then washed their hands with bar soap, after which a second person washed with the same bar of soap. The second person’s hands were cultured and researchers found the bacteria were not transferred. They concluded [10]:

  • Bar soaps do not support the growth of bacteria under usage conditions.
  • Bar soaps are inherently antibacterial by their physical-chemical nature.
  • The level of bacteria that may occur on bar soap, even under extreme usage conditions (heavy usage or poorly designed nondrainable soap dishes), does not constitute a health hazard.”

…another study [in 1988] [11] (sponsored by a soap manufacturer) confirmed these findings.”

Soap is actually saponified fatty acids.  Huh?  

  • You start with a fatty acid from a vegetable or animal fat, such as coconut oil, tallow, or lard. For example, lauric acid (the most common fatty acid in coconut oil).
  • You also need a caustic alkali (lye or washing soda).
  • Then heat them together in a water bath to get soap.  A soap made of lauric acid and lye would be called “sodium laurate.”

Cleaning101-1 (1) has a good description of the chemistry of soap making, with good illustrations.

Most soaps lather well and are gentle and non-drying if rinsed well.  To ensure a good rinsing, mix a little vinegar with water for the rinse. (Note that real vinegar is also anti-microbial).

Castile is a soap made primarily from olive oil, although other oils such as palm, coconut, almond and hemp can be included; you can make this in your kitchen (see Making Real Soap at Home for recipes).  The most popular brand of Castile in the US is Dr. Bronners; another is Kirk’s Castile.  Animal fats can also be used (tallow or lard), but then it isn’t Castile.

If you have hard water (high mineral content), soap will likely leave a hard-to-remove soap-scum ring in your sink, washing machine or tub.  This is because soap combines with the minerals to form a substance that is not soluble in water, and will precipitate out. This is one of the reasons detergents were developed, because detergents do not precipitate in the presence of minerals. (Other reasons include detergent’s superior grease-cutting ability). But remember, household detergents are NOT antimicrobial.

See KitchenDoctor (8) for more history and information.

Detergents, at least the kind we use with water in our homes, are also made from fatty acids, but have a sulfate group added, as in “sodium lauryl sulfate.” Many also have a phosphate group. They cannot be made at home.

The making of commercial detergents typically involves petrochemicals (substances from petroleum) as the source of the fatty acid, strong acids or oxidies of sulfur, and industrial heat and pressure.  In more recent years, manufacturers have found a way to make detergents from plant-based fatty acids, but that does not mean they are better for you, nor that they can kill microbes.  Cleaning 101-2 (2) has a good description of the chemistry of detergent making, with good illustrations.

Generally, detergents – at least those for home use – produce more bubbles than real soap; this is one of the reasons why modern homemakers are reluctant to give up detergents in favor of soap, as they believe the bubbles are required for the cleaning ability.

Household detergents can be quite harsh and drying, and can provoke allergic responses (such as dandruff and eczema).  For this reason, most have extra oils added to mask the drying effect.  And, like most things made from petrochemicals, they are not good for the environment, especially those that contain phosphates.

Making Soap at Home

This section has been moved to its own post: Making Real Soap at Home.


  3. (see recipes 1, 2, 3, & 4)
  9. Mercola articles:
  10. American Journal Public Health Nations Health, 1965;55(6) or
  11. Epidemiology and Infection, 1988;101(1):135

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