Recipe for Kombucha SCOBY

A SCOBY is a Symbiotic Culture Of Bacteria and Yeast which is used as a culinary symbiotic fermentation culture (starter) consisting of lactic acid bacteria (LAB), acetic acid bacteria (AAB) and yeast which arises in the preparation of sour foods and beverages such as kombucha. In its most common form, SCOBY is a gelatinous, cellulose-based biofilm or microbial mat found floating at the container’s air-liquid interface.

When dried, the SCOBY can be used as leather alternatives and paper-like thin materials. Following this procedure, you can grow a SCOBY to use it as a material.

A SCOBY is a living thing, therefore it will react to differences in environment, temperature and small differences in water quality. Because it is living it will therefore also adapt to these environmental changes and you will have a slightly different outcome each time. There are many ways to get your SCOBY to grow thick enough to use as a material. This recipe will teach you a basic growing procedure with a provided SCOBY to start your own culture but you will have to experiment to find what works best for you!

Note: this recipe is meant to provide tips on how to grow a SCOBY for material use. Whereas the process is safe to do, it does not cover a process for human consumption per se, and cannot guarantee safe food practices. 

RECIPE
Ingredients for 500 mL Kombucha

Tip: Try to work as clean/sterile as possible throughout!

• A (piece of) living SCOBY
• 50mL Kombucha liquid “mother”
• Alcohol 70% or a good cleaning with soap and hot water
  • to desinfect all your tools and pots
• Water – 500 ml
  • to make tea
• 1.5 g (1 bag) black or green tea
  • organic teas work best
• sugar – 50 g
  • white sugar or cane sugar
• Vinegar (if the “mother” culture has not been refreshed for long, and is therefore not very active)

TOOLS

• A glass or plastic jar of 0.5/1L
  • try to get a wide one, min 10 cm diameter, with a lid or cheesecloth
• A water cooker or anything to boil water
• Kitchen paper, clean towel
• Soap
  • to wash your hands, anti-bacterial
• A scale
• A spoon
• A thermometer
• PH paper (optional)

METHOD
Create a sterile environment

• Wash your hands with soap for at least 20 seconds
• Sterilize all your tools and Jars with 70% denatured alcohol
  • If you don’t have alcohol: sterilize with boiling hot water.
  • Tip: Be careful with boiling water in a glass container, not all containers can handle the sudden change in heat and can break!

Prepare the sugary tea

• Boil the water
• Add the teabag and turn off the heat.
  • Let the tea brew for 5 minutes (for black tea, or 3 minutes for green tea)
• Take out the teabags with a sterile/clean tool
• Let it cool all the way down to 30 degrees Celcius (so you don’t kill the bacteria of the SCOBY by heat).

Making the Kombucha

• Pour the tea into the jar
  • depending on the size of the jar but it needs to be at least 5-6cm deep
• Add the Kombucha liquid “mother”
• Eventually, measure the pH (acidity) of the mixture
  • it should be around pH 4
  • optionally: add some vinegar to decrease the pH to 4
• Add the SCOBY and close the lid
  • the SCOBY needs air but you don’t want fruit flies so either seal it with cheesecloth or open and close the jar once a day

Growing the SCOBY

• Put it in a warm place but away from direct sunlight (preferably in the dark, like a cupboard), and leave it for 2-3 weeks, or until it has grown 5-8 mm thick (to create paper-like SCOBY) or closer to 10-15 mm thick, to grow for leather-like SCOBY.
  • Tip: Do NOT move the jars too much, the SCOBY will sink and you will have to start over
• Check regularly for unusual growth. Ideally, your SCOBY becomes a thick whiteish film skin-like floating on top of the liquid. It takes experience to learn what unusual growth looks like, use the resources for reference material
• Use your SCOBY

Next steps

• If it has grown to a good thickness, you can use your SCOBY to make paper (about 5 mm) or leather (as thick as possible) or kombucha tea to drink (if all is food safe).
• Take it out with clean hands (or a tool)!
• Re-use the liquid to grow more SCOBY, it now has more living culture in it.
  Make some more sugary tea as described above and add it to the liquid from the previous brew. Use more sour liquid from a previous brew to have faster SCOBY growth.

Tip

Instead of adding tea, you can also continue brewing by adding just sugar, or sugar with beer or wine. Adding natural food dyes will change the color of your SCOBY! Experiment with it to see what you can achieve!

REFERENCES

• KOMBUCHA SCOBY by Loes Bogers (Fabricademy, Waag), 2020: link
• How to Make Your Own Kombucha SCOBY by Emma Christensen for Cooking Lessons From the Kitchn, 5 june 2019: link
• How to Start Brewing Kombucha Without a SCOBY by Kathleen Quiring, for Becoming Peculiar, 6 November 2013: link
• How to Grow a Kombucha SCOBY from Bottled Komucha by Carol Lovett, for Ditch the Wheat, n.d. link
• How to Grow a Kombucha SCOBY Kristen Michaelis, 2 February 2018: link
• Kombucha Mold Information and Pictures by Kombucha CAmp, n.d. link
• SCOBY hotel video quick tip by Kombucha Camp, n.d. link
• SCOBY hotel maintenance by Kombucha Camp, n.d. link
• How to Trim SCOBYS: Kombucha Care by Kombucha Camp, n.d. link
• The NOMA guide to Fermentation by René Redzepi and David Zilber, Foundations of Flavour 2018.
• Kombucha by Cecilia Raspanti (Textile Lab, Waag), Fabricademy Class “Biofabricating”, 2019, link.
• How to Grow a Kombucha SCOBY in just 10-12 days by Brod and Taylor, n.d. link
• A Review on Kombucha Tea—Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus by Rasu Jayabalan, Radomir V. Malbaša, Eva S. Lončar, Jasmina S. Vitas, Muthuswamy Sathishkumar, in Comprehensive Reviews in Food Science and Food Safety, 21 June 2014: link
  • Open Source Kombucha, by thr34d5. n.d., link
• Biofabricating Materials by Cecilia Raspanti for Fabricademy 2019-2020: link
• Grow your own clothes TED talk by Suzanne Lee, 2011: link
• Kombucha Fashion by Cameron Wilson, Peter Musk and Jimmy Eng for the The Edge, State Library of Queensland, n.d. link
• QUT reveals how you can make your own leather at home by The Conversation, republished by SmartCompany, 24 November, 2016: link
• Kombucha 101: Demystifying the Past Present and Future of the Fermented Tea Drink by Christina Troitino for Forbes, 1 Feb 2017:link
• Why is PH important for brewing kombucha? by Fermentaholics, n.d.: link
• Kombucha: the balancing act by Len Porzio, n.d. link
• What’s in my kombucha? by Cultures for Health, n.d. link