Suds Up: How to Make Soap, 19th-Century Style

More

In preparation for an upcoming summer event, the Smithsonian leads us through saponification, the chemical process of creating soap

Saponification-Post.jpg

Piqued by the innovation, resourcefulness and ingenuity required in an era before washing machines did all the scrubbing for us, we decided to make our own soap.

The museum is finalizing preparations for an upcoming summer program, "Wash, Rinse, Wring, Repeat!: 19th Century Laundry at Home." Slated to launch June 11, the program will examine the development of laundry technology over time and invite visitors to wash linens using methods unfamiliar in this day and age.

To get us in the nineteenth-century mindset, Christopher Wilson, Director of Daily Programs, guided the staff through saponification (the chemical process of producing soap) as it would have been performed by Americans a century ago. With only a few modifications (e.g., a hot plate rather than an actual fire to heat the animal fat), we produced an unscented batch and another infused with peppermint oil extract.

Take a look at how we saponified to success:

6a00e553a80e108834015432e4ae74970c-250wi.jpg

STEP ONE: Collect and melt the fat.

Soap has three main ingredients: fat, lye (sodium hydroxide) and water. It is crucial that these components are precisely measured and kept at appropriate temperatures throughout saponification.

We began by melting large containers of cold animal fat. Many different kinds of fat can be used to make soap, and we chose a combination of leftover bacon grease and drippings from roasted chickens and turkeys -- the smell reminded me of Thanksgiving dinner.

Numerous soap recipes can be found on the Internet, but we liked Snowdrift Farm's website in particular because it allows readers to specify the oil in use.

To the right is a photo of Chris explaining the importance of melting points as we melted the fat into oil on a hot plate.

STEP TWO: Combine the lye and water, and bring the mixture to the right temperature.

After melting the fat to the right temperature (we used a chemical thermometer from The Lemelson Center's Spark!Lab), we determined the weight of the fat (this time, with the help of Spark!Lab's digital scales). Next, we combined water and lye, and I was surprised by how quickly the temperature rose upon combination.

According to Chris, nineteenth-century Americans had to be careful when adding the lye: too much and the solution can become very caustic and leave chemical burns on the skin.

Below, you can see Chris mixing the lye and water.

6a00e553a80e108834014e8904b160970d-300wi.jpg

STEP THREE: Mix all the ingredients together, and let it set for a month.

Once the oil and water/lye combination were all set, Chris brought them together in a bowl using a (decidedly non-period-appropriate) electronic hand mixer. The solution quickly transformed into a thick, light yellow liquid. I can only imagine how tiring the process must have been without the help of a handy electric appliance. We then poured the soap into a container, where it will rest for a few weeks before we kick off our laundry program on the National Mall terrace.

The picture at the top of this page shows Chris combining the oil and water/lye solution.

Between melting the fat and working with a substance like lye, saponification can be dangerous and cause serious burns if one does not take the appropriate cautionary measures. If you decide to make soap on your own, be sure to wear safety goggles and use heat-resistant gloves like we did.

The saponification lesson made me feel like I was back in school: hearing words like "melting point," "caustic" and "chemical reaction" reminded me of the degree to which science can dictate our everyday lives -- and even household chores. We hope you come visit the "Wash, Rinse, Wring, Repeat!" program at the museum this summer, and suds up!

Do you have any science lesson stories to share? Have you ever made soap, or even done laundry without the help of modern machines? Share your thoughts and comments below.

See more posts from and about the Smithsonian.


This post was originally published on the National Museum of American History's O Say Can You See?" blog and is republished here with permission.

Images: Smithsonian Institution.

Jump to comments
Presented by

Julia Imbriaco is a seasonal floor manager in the Department of Daily Programs at the Smithsonian Institution's National Museum of American History.

Get Today's Top Stories in Your Inbox (preview)

A Delightful, Pixar-Inspired Cartoon About the Toys in Your Cereal Box

The story of an action figure and his reluctant sidekick, who trek across a kitchen in search of treasure.


Elsewhere on the web

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register. blog comments powered by Disqus

Video

Juice Cleanses: The Worst Diet

A doctor tries the ever-popular Master Cleanse. Sort of.

Video

Why Did I Study Physics?

Using hand-drawn cartoons to explain an academic passion

Video

What If Emoji Lived Among Us?

A whimsical ad imagines what life would be like if emoji were real.

Video

Living Alone on a Sailboat

"If you think I'm a dirtbag, then you don't understand the lifestyle."

Feature

The Future of Iced Coffee

Are artisan businesses like Blue Bottle doomed to fail when they go mainstream?

Writers

Up
Down

More in Technology

Just In