Garbage collectors

Shanghai residents learn how to make garbage enzyme. Photos: Du Qiongfang/GT and courtesy of nipic.com

Turning leftover fruit and vegetables into a versatile household product

With a rise in the number of allergies and worries over exposure to chemicals, more people are looking for alternative ways to clean their homes.

To this end, some people are turning to the use of garbage enzyme - a concentrated liquid produced from fermented fruit and vegetable waste. Garbage enzyme can be easily produced in the home, and has many uses, including as a cleansing agent, insect repellent and even shampoo.

At the same time, it is hoped that the production and use of garbage enzyme will help reduce household waste and encourage people to take the initiative in sorting their trash.

The concept of using home-produced enzymes entered China several years ago when a special bucket imported from Japan was promoted by some health experts as a means of making healthy drinks. The bucket could be used to make enzyme solutions from fermented fruits.

While the effectiveness of the enzyme drink remains unproven, garbage enzyme has been shown to be effective as a detergent for cleaning toilets and floors, and as a fertilizer for plants.

According to Shen Yike, director of ecological protection association Friends of Nature Shanghai branch, making wet garbage into an enzyme solution has been practiced in Southeast Asian countries for decades, greatly reducing household waste and protecting the environment by reducing the use of bleach and other strong chemicals.

"Many people have realized that chemicals do harm to human body and the more garbage enzyme they make, the more good it does the environment," said Shen.

Any reduction in the volume of household garbage will benefit the city. Shanghai produces the largest amount of garbage than any other city in China. It is also home to the largest refuse landfill in Asia, the Laogang Refuse Landfill in Pudong New Area, which occupies a total area of about 30 square kilometers. It is struggling to accommodate all of the city's garbage, with a fifth phase under construction. The landfill and its surrounding areas are heavily polluted, something that nearby residents have been complaining about for years.

"The process of making enzyme solution consumes wet garbage," said Shen. "This means residents don't produce wet garbage after they start to make garbage enzyme. They even find the amount of wet garbage produced by their families is insufficient, so that they have to ask for garbage from their neighbors."

Another advantage is that producing garbage enzyme encourages people to think more about garbage separation - something the local government has been trying to encourage but which still is not practiced by many residents.

Garbage treatment is a crucial issue, especially for a metropolis like Shanghai. The city's population of more than 23 million people produces an average of nearly 20,000 tons of garbage per day. At the current rate, by 2015 that figure will be 22,000 tons per day.

"As an environmental protection volunteer, I have been looking for a method to encourage individuals to take the initiative to classify their garbage," Shen said. "I found that those who enjoy making garbage enzyme are always willing to classify garbage, because they cannot make enzymes unless they classify the garbage correctly."

There are already hundreds of homemade enzyme enthusiasts in the city, who exchange their knowledge and experience with each other online.

Lü Xia of the Enzyme Workshop club found out about garbage enzyme at a lecture she attended. The lecture introduced many uses for garbage enzyme, including using it to make shampoo.

Lü found store-bought shampoo and conditioner made her hair dry and her scalp itchy, so she decided to give garbage enzyme a try. The lecturer gave her the recipe for a shampoo enzyme mixture. "I reduce the amount of shampoo used in the mix each time, and my hair is not so oily now and has more body," said Lü.

A volunteer helping to promote the use of garbage enzyme in Pudong New Area who asked not to be named said she thought making garbage enzyme would be too much trouble when she first heard about the practice. But another volunteer in her compound suggested she use garbage enzyme to get rid of a lingering smell of fish in her kitchen. After spraying the enzyme mix in her kitchen, the smell disappeared. Since then, she has been making her own enzyme. She has also found that spraying the enzyme in her home every day repels mosquitoes and other insects.

The process of making homemade garbage enzyme was developed by Rosukon Poompanvong from Thailand, who researched garbage enzymes for over 30 years. The ingredients include water, brown sugar and vegetable and fruit waste. A container is needed in which the waste will be fermented for a total of three months - any plastic bottle, jar or bucket with a lid will do.

The brown sugar, clean vegetable skins and water are put in the container in a 1:3:10 ratio. The lid is then securely fastened and the container left for 24 hours. The cap must then be removed to release the buildup of gases caused by the fermentation. This must be repeated for a month. For the last two months, the container can be left to stand, as gases will no longer build up.

The process can last longer in winter when temperatures are lower.

When the fermentation is completed, there will be a layer of white material covering the dark brown solution. This white layer must be skimmed off. The remaining solution can be used neat or diluted.

Guo Ruqi, a volunteer from Friends of Nature who has been making garbage enzymes for around three years, said her family were against the practice when she first started.

"My family could not understand why I spent so much time on it," she said. "But I continued to make garbage enzyme and I use it in daily life. My family members soon discovered that it is really useful, and they now help me to make it," said Guo.