Welcome to Geektoberfest 2021

The Science of Fermentation

Fermentation comes in many different forms. Many of the fermented beverages we often encounter use yeast as the factory for fermentation, including beer and wine. In these beverages, fermentation starts when yeast are added toward the end of the production process. The yeast eat the sugar molecules present in the liquid and produce alcohols. This also generates CO2 gas, causing many bubbles to appear. Working on their own, these microbes are able to get a lot done!  

In kombucha tea, however, the process goes a step farther. Kombucha contains both yeast and bacteria. These microbes work together to ferment the sweet tea — they actually need each other to thrive! The bacteria in the culture eat the alcohols made by the yeast and turn them into acids. This is what makes your culture smell a bit like vinegar. As fermentation progresses, the tea gets more and more acidic, which makes it hard for other microbes to invade and steal their food. You can see why these microbes are such a good team! 

Here is a fun, family-friendly activity for you to make leather from kombucha at home:

Recipe 

Mix Time: 30-45 min  |  Grow Time: 7+ days | Dry Time: 1-2 days  |  Create: 30 min
Key Concepts: Living systems, biomaterials, microbes, fermentation 

Making with Microbes PDF Activity

What you need:

• Heat-safe container
• 3 teaspoon of honey or agave syrup
• 3 cups of water
• 1 tea bag or 2 teaspoon of non-herbal tea leaves
• 1 quart growth container
• Bottle of kombucha (non-flavored)
• Clean cloth (coffee filter or cheesecloth)
• Rubber band 
• Non-metal surface

Instructions:

1. Boil water in a heat-safe container. 
2. Add sugar and tea leaves to steep. Let the tea cool.
3. Add cooled tea into a clean growth container. Add a bottle of kombucha.
4. Cover the opening with a clean cloth and rubber band.
5. Leave to grow for at least a week or until the amount of biomaterial you want has grown. Try not to move it!
6. Wash your hands and remove the biomaterial. Lay out on a non-metal surface until dry.
7. Peel the dry biomaterial from the surface and make some awesome creations!