As seen in issue 39 of Good, Skye Wishart looks into the world of fermentation and how these foodstuffs can help our health. Here, she explains one fermented food in particular.
What is Kombucha?
Kombucha is also known as Kargasok tea, tea fungus, haipao and Manchurian mushroom. After fermenting sugary tea with a kombucha culture for 1-2 weeks, fruit juice can be added to taste, then it’s bottled without the culture and consumed when fizzy. It’s usually delicious (tart but sweet, and carbonated).
But for me as an uninitiated fermenter, to get past my squeamishness I had to know exactly what this slimy disc of kombucha culture called a ‘mother’ of ‘scoby’ was – and what it was doing to the tea and juice – before I would go anywhere near it.
SCOBY stands for Symbiotic Culture of Bacteria and Yeast. Basically, the floating disc of jelly-like stuff is a whole lot of different types of bacteria and yeast, hanging out happily together, held in a disc of cellulose mostly made by one or two of the bacteria species. It’s related to the ‘mother’ that is used to make vinegar. To grow, all the kombucha bacteria and yeast need is sugar, and at the right temperature. Tea has a few things the bacteria need also, like nitrogen, and has health benefits for the drinker.
The various bacteria and yeasts produce things like acetic acid (vinegar), gluconic acid, carbon dioxide (the fizz), ethanol (alcohol, a tiny amount usually less than 1 percent), complex B vitamins, and folic acid. They also build the scoby up further.
What kind of bacteria are they?
All sorts; the exact mix varies and depends on where you got your scoby from – no two cultures are the same. It includes acetobacter xylinoides and acetobacter ketogenum. There’s luconacetobacter kombuchae which is only found in kombucha. Sometimes Lactobacillus is in there too. The yeasts involved are mostly Saccharomyces cerevisae, the same one used in breadmaking and brewing, but there are others including Zygosaccharomyces kombuchaensis which is a yeast found only in kombucha. And yes, many of these will be lingering in the liquid so you’ll be drinking them – but that’s a good thing.
Kefir grains are another culture used to make delicious drinks. Like kombucha, they’re a combination of bacteria and yeasts, but surrounded by a biofilm that one of the bacteria strains will have made, so that they form little separate ‘grains’. These microbes work in either water-based liquid, or dairy, depending on the type – rather than the tea that kombucha relies on.’
More fermented frenzies
Directly translated to mean “sour cabbage”, saurekraut is finely cut cabbage that has been fermented by lactic acid bacterias including Leuconostoc, Lactobacillus, and Pediococcus. When the bacteria ferments the sugars in the cabbage, lactic acid froms resulting in a long shelf life and a distinctive sour flavor. Sauerkraut is a popular condiment to support meat dishes and snacks such as hot dogs and will keep in the refrigerator for 1-2 months in a sealed jar. Fermented vegetables are extremely important for good gut health and are great to eat if you are suffering from digestive problems.
Yoghurt is a fermented milk product produced by bacterial fermentation of milk. The texture and flavour that yoghurt is known for is derived when lactic acid is produced and acts on milk protein during the fermentation process.
Dairy yogurt is produced using a culture of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus bacteria. As well as this, other cultures such as actobacilli and bifidobacteria are occasionally added during or after culturing yogurt.
Yoghurt is a common and popular item in fridges, boasting a wide range of health benefits. It is naturally rich in protein, calcium, vitamins D, B6, B12 and more.