Soap Butterfly Effect — The Butterfly Effect of a Single Bar of Soap

Soap Butterfly Effect — The Butterfly Effect of a Single Bar of Soap

Yi Yun, founder of the zero-waste studio Casamu, believes that when good, healthy scents touch the body, the joy of life doubles.

Interviewer Parc Jinmyoung
Interviewee Yi Yun (Founder of Casamu)

March 30th was the first-ever World Zero Waste Day, established by a resolution adopted at the 77th United Nations General Assembly in New York last December to promote sustainable consumption and production. This global movement makes it clear that now is the time for everyone to join the conversation around zero waste. Yi Yun, who runs the zero-waste studio Casamu, says that ‘a zero-waste life begins with changing the everyday products we use.’ How can the flutter of zero-waste products—cosmetics, cleansers, perfumes made with harmless ingredients—change the world?

Could you give us a brief introduction to Casamu?
It's a studio that makes zero-waste everyday products—soap, cosmetics, perfume, detergent—and offers aromatherapy education. I run it hoping that many people can care for their body and mind through scent and build a healthier lifestyle.

What inspired you to start Casamu?
At some point I began worrying about the toxicity of mass-produced products and how poorly microplastics break down. That led me to wonder which ingredients were harmless to the human body and the environment, and I wanted to make products myself using healthy materials. As I became interested in a healthy life, I naturally started thinking about the environment too. What's good for the body turns out to be good for the environment as well. Wanting to share what I'd learned with others, I opened Casamu.

What's the biggest change in your life since you started reducing waste?
As the amount of trash I produce has decreased, my everyday life feels lighter and fresher. Another big change is that it's inspired the people around me to take action too. I never really urged or pressured anyone, but my family and friends have been influenced and gradually joined in, one by one.

What makes the soap Casamu makes special?
It's a mildly acidic soap made only with naturally derived surfactants and plant-based oils—also called a neutral soap. Since a soap's function changes depending on which ingredients are used, I think the biggest advantage of handmade soap is being able to choose ingredients suited to each person's skin and create a customized bar.

What do you pay the most attention to while running your zero-waste classes?
Honestly, nothing grand. It's just about reducing waste one step at a time. Since I started making my own household products, the amount of plastic I use in daily life has dropped dramatically. From bathroom items to dish soap, laundry detergent, fabric softener, and antibacterial spray, with just a little effort you can switch to eco-friendly alternatives. It's not only about reducing trash but also about reducing the chemicals that build up in your body.

Convenience is probably the biggest enemy of a zero-waste life. Do you have any personal tips for embracing the inconvenience willingly?
As I mentioned, it's about cutting back one thing at a time. If you go in expecting big changes right away, I think you're more likely to get discouraged and give up. Everyone has a different threshold for how much inconvenience they can tolerate. It's best to start from a place of ‘I can handle this much for the sake of the environment.’ If you set an absolute rule like ‘never do this,’ you'll feel guilty every time you break it. I recommend practicing slowly, starting with small things.

Was there a travel destination or spot that inspired you when opening Casamu?
Before opening Casamu, I traveled around the world, and I spent a year living in San Cristóbal de Las Casas, Mexico. It's a city formed in a highland region at an elevation of 2,200 meters, largely untouched by modern civilization. With a population of about 200,000, it's small but has a vivid, distinctive character. I fell so in love with its charm that I lost track of time there. Manufactured goods were so expensive that most residents made whatever they needed by hand. During my time there, I too started making what I needed myself, and my unnecessary consumption dropped. I think that experience is what led me here.

Is there a destination you'd like to visit related to eco-friendly products or lifestyle?
I'd like to visit New Zealand, a country truly devoted to nature. In a place where eco-friendly living has already become the norm, I'm curious how small sustainable brands similar to Casamu market themselves and sustain their business. Germany is another country willing to invest money and time in the environment. I'd love to visit workshops and shops there that make eco-friendly products.

Do you have an episode where you were inspired while traveling?
I think I get a lot of inspiration from markets while traveling. Like in Mexico, which I mentioned earlier, many countries in Europe don't use plastic bags either. Even ten years ago, when I was in the middle of my world travels, carrying your own tote bag was already a normal part of daily life. Seeing those everyday attitudes and small practices made me want to change too.

What's the easiest way to start practicing a healthy lifestyle?
There's a saying that you are what you eat. I think the same goes for the products you use. If making your own products feels too difficult, choosing products with healthy ingredients that don't harm your body or the environment is also a good approach.

What are your future plans or goals?
I'll never let zero waste and sustainability become just a passing issue. I plan to keep practicing an eco-friendly lifestyle in my own way, steadily.