In recent weeks, I've received a flurry of questions all asking the same thing, "I've read there's fluoride in kombucha. Should I be worried?"
There certainly is fluoride in your kombucha, because there's fluoride in your tea (there's also fluoride in your wine and your black pepper). It's difficult to say just how much fluoride is in your kombucha because the quantity of fluoride in your brew depends heavily on the quality of your water, the quality of your tea, and other factors surrounding how you brew your kombucha, as you'll read below.
Should you worry about fluoride in kombucha?
Fluoride that accumulates in tea (and, therefore, your kombucha) is calcium fluoride, a form that is different from the type of fluoride added to municipal water. While your body benefits from fluoride in small amounts, you can consume too much. There have been cases of fluorosis occurring among people who drink excessive amounts of strong, cheap tea.
Unless you're drinking several quarts of kombucha made with strong, cheap tea, there's no need to worry.
Fortunately, those cases are extremely rare and are easily mitigated by consuming modest to moderate amounts of high-quality tea and kombucha made from high-quality tea. Remember, further, that kombucha is made from weak tea, rather than strong, so there will be less fluoride in kombucha than a strong tea of the same volume, as explained in the Big Book of Kombucha.
I don't worry about relatively small amounts of fluoride in the modest amounts of kombucha my family drinks.
Where does the fluoride in kombucha come from?
Fluoride in kombucha comes from two sources: the tea and the water you use to brew your kombucha.
Fluoride in Municipal Water
If your community adds fluoride to its water, and you brew kombucha, without filtering your water, your brew will contain fluoride. If you use spring water or well water, fluoride in your water shouldn't be a concern unless you live in a fluoride belt with high levels of naturally occurring fluoride. It’s wise to test your water if fluoride levels concern you.
Fluoride in Tea
The tea plant takes up fluoride and also aluminum from the soil in which it grows, just as rice takes up arsenic and grapes take up lead and fluoride. Fluoride also accumulates in other plants like black pepper and mustard seeds. All plants take up minerals and heavy metals from the soil.
Much of the fluoride that tea accumulates occurs naturally in soil, and certain regions have higher concentrations of naturally occurring fluoride in their soil and water than others such as Africa, India, Sri Lanka, and some parts of China. Fluoride also accumulates in the soil due to environmental pollution and conventional agricultural practices.
Still Worried? How to Reduce Fluoride in Kombucha
If you're still concerned about fluoride in your kombucha, but still wish to continue drinking it, there are a few steps you can take to minimize how much fluoride ends up in your brew.
Brew with Filtered Water
Brew kombucha from filtered water or water that hasn't been treated with fluoride. If you use a natural spring or well water, you don't need to do anything, but if you're on municipal water that's fluoridated, consider filtering your water.
Both gravitational systems, like point-of-use filters, and whole house water purification systems like these when equipped with fluoride filters should be effective in mitigating the fluoride from fluoridated water supplies.
Brew with High-Quality Organic Tea
Much of the fluoride that the tea plant takes up and deposits within its leaves comes from inputs used in conventional, but not organic, agriculture. These inputs accumulate in the soil and are then taken up by the tea plant. Since these inputs are not allowed in organic products, the fluoride content of organic teas is typically lower than that of those grown conventionally.
Further, higher-quality teas accumulate less fluoride than low-quality teas, there's such a distinct correlation between tea quality and fluoride content that you can judge the quality of tea by the amount of fluoride it contains. Excessive consumption of low-quality tea is associated with fluorosis, but it's not an issue with moderate consumption of high-quality tea.
Lower quality teas are made from older leaves, with younger leaves used in higher quality teas; further, as tea leaves mature they accumulate more fluoride and they lose antioxidants. By brewing with younger leaves, as found in high-quality teas, you'll get more antioxidants and less fluoride.
Brew with White, Green, or Puerh Tea
White teas, puerh tea, and green tea typically have lower levels of fluoride than black tea. Puerh tea, in which tea leaves are fermented before being dried and packed, has some of the lowest levels of fluoride and is unlikely to induce fluorosis.
White tea is a particularly good choice (and what I brew with) as it is made from young leaves, has a very high antioxidant content, and high antioxidant content is inversely associated with fluoride: that is, the more antioxidants in tea, the less fluoride and aluminum.
Steep Your Tea for a Shorter Period of Time
The longer you allow your tea to steep, the more fluoride will accumulate in your infusion (more here), with tea steeped for over ten minutes having the highest concentration of fluoride and tea steeped for two minutes the least.
Incidentally, the longer you allow your tea to steep, the more you lose in terms of its more delicate flavors and the more tea's bitter tannins will develop so be mindful of your steeping times and temperatures (this guide is a good one).
Drink modest amounts of kombucha
When you can buy kombucha in 16- to 40-oz bottles at the store, you might think that it's appropriate to drink kombucha all day long, right? It's a health elixir, isn't it? A fermented tonic, right?
The thing is that kombucha isn't intended as a substitute for water or something that you guzzle all day long. It's a tonic rich in B vitamins and beneficial microbes that are best consumed in modest to moderate amounts. If you need hydration, choose water.
Drink something else
If you're still concerned about fluoride and trace amounts of aluminum in your tea and kombucha, consider drinking other fermented drinks that are made without tea, such as water kefir, beet kvass, and tepache, or other fermented drinks made with a ginger bug or fresh whey.
Quick Resources for Reducing Fluoride in Kombucha
Remove fluoride from your water by using a water filtration system with a fluoride filter.
Use high-quality loose-leaf tea made from young leaves like white tea.
Steep your tea for a shorter amount of time, I use this programmable electric tea maker which always brews tea at the right temperature and for the right amount of time, or you can use the timer on your phone to keep an eye on the time and avoid oversteeping.
Drink modest amounts of kombucha, a few ounces each day, and balance that with plenty of water, herbal teas, and other probiotic beverages.