Kombucha is a delicious, healthful beverage that I just LOVE. I’ve been making it for several years now, and at the height of the summer when it’s Kombucha season, you can find this yumminess brewing in 5-gallon pails in my home kitchen. Over the years, I’ve heard many people refer to this amazing being as a “mushroom”. Sure, it looks like one, but it’s not. That creamy colored mass that floats on the surface is called the SCOBY. SCOBY stands for Symbiotic Culture of Bacteria and Yeast.
The keyword here is “culture” Just like our Kootenay “culture” consists of many people, pets, trees, mountains, plants, skis, bikes and the like, a Kombucha culture is equally as diverse. Inside the Kombucha culture you’ll find many microscopic beneficial microorganisms including those of the species Acetobacter and Gluconoacetobacter. Each culture will not be exactly the same, and some cultures have even been found to contain Lactic Acid Bacteria (the bacteria responsible for lacto-fermented foods such as yogurt, cheese and salami).
The final product, the beverage we know and love is the result of microbial metabolism. Primarily, the Acetobacter and Gluconoacetobacter digests the sugar and create acetic acid as a by-product, giving it it’s characteristic sour taste.
So what’s with that gelatinous mass that floats on the surface anyways? It’s why most people think it’s a mushroom, but to be perfectly clear, it is not a mushroom. In fact, this mushroom-like mass is actually a BIOFILM.
A biofilm is a slimy film of bacteria that adheres to a surface. In the case of Kombucha, it forms on the surface of the concoction. The cells of the culture will adhere to this surface, but nature is so efficient that it’s given Kombucha’s biofilm more than one purpose. It protects itself from insects, dust, sneezes, etc. Nature had it’s own food safety plan!
In my sticky adventures of home Kombucha brewing, I’ve seen insect larvae growing on the surface of the scoby with the beverage underneath it completely unaffected. Although I’ve curiously sampled it and lived, I don’t recommend drinking, bottling or selling pest-infested Kombucha. I do, however recommend that you use an additional layer of protection from pests, such as a piece of fabric, cheesecloth or clean dish-towel to tightly cover your fermentation vessel.
I talk about biofilms a lot – if you’ve ever attended one of my food safety workshops, this is not news to you. This article is my sneaky way of talking about two things in life that I am passionate about: Kombucha and Food Safety. The biofilm that a Kombucha culture grows is beautiful and truly amazing. In food production, we’re familiar with less friendly biofilms, the kind that harmful bacteria like Listeria can grow on. Once you have a biofilm in your facility, it is very difficult to eradicate and you’re left with a source of contamination. They’re like petri dishes that we use in microbiology to culture or grow a microorganism, and the surfaces of your food production facility likely provides the ideal conditions for growth – food, low acidity, warm temperature, oxygen, moisture, and time.
Now that you know that there are friendly microoganisms and not-so friendly microorganisms, I want you to let that piece of information settle. Do you see that not all germs are bad? Some are very beneficial, while some will be harmful.
So how do we discern the difference and manage food safety? If a microorganism can cause harm to human health – and that includes spoilage bacteria – then it’s harmful and needs to be managed as a hazard in our food safety operations. A good place to start is by reviewing your sanitation plan to ensure that it is adequate to maintain your facility in a sanitary condition. Build your sanitation plan to make conditions for microbial growth less than ideal. This means regular, scheduled thorough cleaning and sanitation of the premises, ensuring the removal of steam and moisture, proper cold storage where necessary, and sterilizing food contact surfaces. This will go a long way in preventing the formation of unfriendly biofilms.
If you want the opportunity to experience, observe and appreciate the beauty of the Kombucha culture, I have a free giveaway. Comment and share this article with your friends and on April 10, 2017, I will draw at least 5 names. Winners will receive a healthy SCOBY in the mail, or if you’re local we can make other arrangements for delivery. Now go forth, review your sanitation plan, brew some Kombucha goodness and appreciate that not all germs are bad!