Garbage becomes part of our daily life, especially household waste. In general, many people do not care about the waste generated by their consumption habits. Garbage becomes a social problem that arises in society and affects the environment and health. Social problems can be overcome with proper handling through creative ideas in the form of entrepreneurship and skills to process waste into products that have added value for sale. Activities to overcome such a problem can be classified as social entrepreneurship, namely initiating entrepreneurial opportunities to answer social problems.

One of the activities to understand Social Entrepreneurship was held by Stube HEMAT Yogyakarta by giving a training to help students to map and to find ideas from social problems in their area. The students also learned directly by participating in an exposure to Lintas Winongo Garbage Bank, Bumijo RW 11 village, Yogyakarta (Saturday 12/11/2022). At the exposure site, they dialogued with Joko Sularno and Siti Rojanah, pioneers of the Lintas Winongo Garbage Bank and learned the steps from waste collection, sorting process, until ready-to-sell products.

The resource person told about the concern about the waste problem due to the bulk of garbage in residents' homes, both from local dan settlers and there has been no effort to sort it out. They started by raising awareness and inviting residents to create a beautiful and waste-free environment through the Garbage Bank. Garbage which became a social problem turned into an opportunity with the founding of Lintas Winongo Garbage Bank. Since 2009, there have been 224 customers with a turnover of 1,5 – 2 million per month, while the Garbage Bank's customer savings have reached 18 million. It inspires other regions to solve problems and even create opportunities for waste problems.

Students gained knowledge and experience from sorting plastic waste, paper, used drink bottles, and used fruit peels, then processing waste into handicrafts and eco-enzymes. With the term Garbage Bank, the term 'customer' is used by residents who collect waste at their homes and sell it at the Garbage Bank. There is a profit-sharing system of 10% of sales proceeds between the customer and the waste bank. Most customers are elderly otherwise and fewer young people or students.

The topic of eco-enzymes provoked Chandra, a student from Kalimantan, who asked about the ingredients for making eco-enzymes. The resource person answered that the eco-enzyme comes from fruit peel waste fermentation. It is made in mineral bottles and requires water and sugar as a source of carbon and fruit skin waste. The fermentation process takes about three months.

From the exposure, students learn about waste and start caring of social problems which can enlighten the public about waste-free environmental management. It is a challenge for young people to care about social problems, find solutions and generate profits to improve the economy and people's welfare. ***