In this design challenge, learners will use microbes to design and grow a custom biomaterial at home and make something creative with it. This biomaterial is made by the millions of living yeast and bacteria that normally work together to produce kombucha, a fermented tea. But, depending on what you feed them, they can also grow interesting and different pieces of biomaterial for you. Includes step-by-step instructions with microbe care tips, an extensive suggested materials list to use when choosing how you want to grow your biomaterial, and suggested personalization extensions. A Spanish version of the activity is also available. Please note: this is a long activity so a quick start guide is included.