Kombucha Too Sour?

What to do when your Kombucha is too sour ?


Understanding zymurgy tells us that Kombucha Tea is fermented sugar and tea.  On the first day Kombucha Tea is Tea. Just like Southern Sweet Tea. Really sweet tea. If we simply allow the kombucha to go on its own course, and doesn't go moldy, it will at some point turn into a light or poor vinegar tea.I say poor because by U.S. regulations require vinegar to be called vinegar must be at least 5% acetic acid and identified by its source.. 

A Sour Kombucha can result from many conditions.

Kombucha, due to its serendipitous interplay between the yeast and bacteria rarely get beyond 2% acetic acid. *1 Yet the taste can be very sharp.

1.   The easiest and most common condition is you just let your kombucha go too long. Say your typical batch is ready in 7-9 days at 82F. You didn’t get around to it until day 11 or 12. Your batch is good just your timing was off. There are a couple of things you can do.

 a.    Blend with some fruit juice or water.

        For small batches and where the intention is to drink it soon, simply add a bit until the taste is pleasant. However on large batches, or when Continuous Brewing you may want to “Bench-Test” . This is a process where you take a small sample and add a measured amount of sweetener or fruit, etc. When you have it just right you can then add the same ratio of sweetener to the larger batch. This helps prevent adding too much sweetener, or finding out that your container is too small to hold it all. Be sure to keep accurate measurements. On Continuous Brewing you want it just a little bit more on the sweet side and allow it to ferment more time. You may want to refrigerate right away before any re-fermentation starts again or add some potassium sorbate to stabilize. 

 b.   Neutralize some of the acids with calcium carbonate or potassium bicarbonate.  Calcium Carbonate (available  where vitamins and minerals are sold) does not dissolve well in water and will leave little pieces floating around. Calcium also leaves a little ‘chalky” taste, well because it is chalk. But Calcium Carbonate was highly recommended by Dr. Robert Barefoot in his book The Calcium Factor where he recommended drinking Kombucha Tea with Coral Calcium (has added minerals) to “cure over 200 degenerative disorders”. Add the calcium slowly, as it will instantly foam up. Recall your high school chemistry days of making a volcano with calcium and vinegar. Potassium also neutralizes acids, is also healthy but I don’t know if it cures 200 disorders. Baking Soda and Powder also works to neutralize acids. You can also use eggshells, or nuts, which are high in calcium. potassium bicarbonate (1/4 teaspoon per gallon). The acids will react with the potassium and create potassium bitartrate - cream of tartar. They form crystals that will fall to the bottom and can be removed. Though that takes some time (Refrigeration for ~30 days).  All these will leave their influence.

Don’t try to neutralize all the acids or you’ll be left with yucky water. A side benefit of these minerals is that in the process of neutralizing some of the acids Carbon Dioxide is released and your kombucha Tea becomes a bit more bubbly. 

Typical Kombucha contains about 33 grams per liter or various acids. These acids are believed to be the main health agents. Acetic acid (vinegar) is the sharpest. Other acids like Gluconic acid and Lactic acid are much milder, pleasant tasting and healthy. In your brewing process obtaining a higher level of these particular acids will allow higher overall acidity (including more acetic acid) while a better taste. That should be your goal. In the meantime adding some lactic acid (kefir whey, Japanese Water Crystals, or other lacto-ferments may balance out your sourness. 

c.    Straining. Straining removes a percentage of mostly yeasts and some of the bacteria and thins out the taste. This removes some of the bitterness. Strain through layers of cheesecloth. The more layers the greater the degree of reduction. Run a hot iron over the cheesecloth first to sterilize.  Straining will also add oxygen back into the brew. This helps the taste profile overall. However if you filter then keep the bottle in a warm spot you’ve just re-ignited a second ferment and your brew will sour more. So only filter what you plan to drink or bottle and refrigerate.  A Second Stage ferment at a very sour stage will just produce a sparking overly sour alcohol drink.

 d.   A slightly sour Kombucha Tea may benefit from Refrigeration for 2-3 weeks. (cold stabilization or chill proofing). Fill the bottle to the top and do not leave any air space. This is a good method of smoothing out a slightly overly acidic kombucha mushroom tea. A portion of the tartaric acid  (if Potassium was used will precipitate out as crystals). Adding Bentonite Clay or other fining agents will also assist this process and help clarify the kombucha tea as well as add valuable minerals.

 e.    Oaking With Chips or Oak Spirals helps refine Kombucha Mushroom Tea that possess more of a "bite." Use about ¾ ounce (20 grams) per gallon, or about 1-2 inches of the Oak Spiral. If using chips then a bag is necessary. Place the chips in a cloth bag with a couple of marbles and tie it off with string. Sink this in boiling water for about five minutes. This removes any harsh tannin from the wood and sterilizes it and the marbles. Then remove the bag, allow it to drip drain long enough for it to cool down enough to handle, and then add the bag to the kombucha. Oak may be added during any stage of the Kombucha process or after during a Second Stage Ferment or during Refrigeration.

 f.     Charcoal. Charcoal is often included in Oaking. When the wood is toasted or burnt. The big advantage of charcoal is that it filters our otherwise impurities to a brew. Such as methanol (relatively toxic alcohol) and reduces acetic acid.  Takes out the bite in most all ferments leaving a more mellow smoother brew.

You can do one or actually all these to your brew. Even if your brew is not too sour. It is far preferable to work with a brew that is good and improving it rather than bringing it back from the dead.

You may decide to allow the ferment to continue to sour. Rack to remove as much of the yeast  a possible. Ferment aerobically with an open top covered with cloth. Just as you did for your initial batch. Place where there is air circulation. If you want to increase the strength of the vinegar-to-be add some alcohol. Everclear is the next to best closest to all alcohol you can get. You can add up to 5% by volume ideally the yeast would be removed. Overall the alcohol is ~6% and there remains some glucose. Roughly that should produce ~ 6% acetic acid in a few months.

There are other reasons why your kombucha tea become sour.

More troublesome is where your brew went off early. Like in a day or two – wow really sour, really fast. This is attributable to the

Weak bacteria. The Gluconobacter (one of 6 species of Acetobacter that produces gluconic acid and the Mushroom) are struggling. This may first be noticed by a less than perfect creamy smooth mushroom. Or by too vinegary taste.

    Acid Balance. Gluconic acid balances out the harshness of acetic acid. Typically the Kombucha ferment will have about 30% more gluconic acid than acetic acid.

For example:

    Braggs Apple Cider Vinegar with >5% acetic acid has a pH of 3.5. 

    Kombucha Tea typically with < 1% acetic acid has a pH of ~ 2.5

    Both healthy. But you can only take a spoonful of ACV. While you can drink a whole bottle of Kombucha Tea


Sometimes caffeine help stimulate the bacteria (use a Black Tea) or the amino acid L-Arginine. Adding a percentage of Glucose to your sugar total and a shot of alcohol all will help jump start sluggish bacteria. The same combination (caffeine, sugar, L-Arginine, and alcohol( is said to work for husbands as well :))

    Bacterial Phage. Phages are non-toxic to humans, and attach the bacteria in 3 known ways: 1) invade the host and multiply with unknown affects, 2) cause erratic behaviour such as mutating to non-cellulose production (lack or poor mushroom formation) 3) kill off the bacteria after reproducing. 


The most common and easiest to fix

2. Yeasts. Either the yeast lack nutrition (Vitamin B1) or the amino acids are lacking oxygen. Third possibility the yeast are stressed by too high of temperatures, or some other stressors. 

    Except for Brettanomyces (yeast) most yeast struggle in too warm of temperatures. Keep your brew around 72-75F. Provide a yeast Nutrient (or Thiamin, B1) Coral Calcium is a good choice, though it does not dissolve readily in water. It does help the pH balance which may also be a challenge for some yeasts. Start with a more favorable pH close to 5. Increase the Oxygen. Shaking, stirring, rock + roll. This gets the yeast to repopulate with a younger more active population.  Black Tea also help the yeast more than other teas, in nitrogen, tannins and purines.  

3. The Balance between the Bacteria and Yeast are out of whack. The ebb and flow of bacteria and yeast create a cycle. When the yeast population is high the bacteria population is low and vise-a-versa. This creates a natural rhythm.  If the above mentioned remedies don't work:   

a.    When this happens don’t look to perfect your brew its already lost. Its not Kombucha anymore, never was.

b.   The most often used remedy. Start over with a spare kombucha mushroom from your kombucha hotel.

c.    Gather the mushroom, rinse off with some non-chlorinated water, and gather 1-2 cups of kombucha tea and some sludge (spent yeast) . Prepare  your sugar and tea. Use Black Tea (not decaffeinated) and steep for 10 minutes or so. Add some Coral calcium or other things mentioned above to neutralize some acids. Add a multiple B vitamin. Add all to the fresh sugar and tea before adding the starter tea. Have the start at a pH of ~4+. Stir well to really add oxygen back into the water. Add the mushroom, cover and sit is warm place ~ 75F


The following are some ideas on How to Use Sour Kombucha Tea

We recommend to filter through several layers of cheesecloth before using to remove any particles, yeast and sugars. And to make a cleaner Sour Kombucha.

Racking after filtering will present a clear more appealing Sour Kombucha.

Restore your pH Balance.

This is a great formula for balancing the Acid/Alkaline ratio in the body and supplies Iron and Potassium. This formula is vital for those with Osteoporosis, Arthritis, and many other debilitating diseases.

1. One cup of well aged (sour) kombucha tea. Really sour is best.
2. One cup of Organic Black Strap Molasses.
Mix together and store in a glass jar and refrigerate and the hungry kombucha will feed on the sugar in the molasses. Careful of glass exploding if left in the heat.

recommended dosage: 2 to 4 tablespoons a day.

Gargle Kombucha Tea Gargle for a sore throat Kombucha Tea and Honey mixed together take before bedtime for a restful sleep. Boil equal parts and inhale the steam for headaches. Nagging cough or sore throat: Drains sinus.

For Really Sour Kombucha

Antiseptic I have used sour kombucha liberally on my dog's hot spots even when he ha chewed himself raw. Almost instantly it calmed him down and allowed the skin to heal within a few days. Works on people too. Applied directly on burns and scrapes. Baby mushroom work best as they can be left in place.

Foot Soak great as a Foot Soak Be sure to well age the kombucha because if there is any sugar left it dries sticky and itchy. Rinse well if there is any sugar left. 

pet wash As a pet wash. Wet a wash cloth in sour kombucha and wipe down your dog, cat or horse. Dirt comes right off without leaving that wet-dig smell.

For softer skin beat an egg white until frothy and add a tablespoon each of honey and Kombucha Let dry completely, then sponge off with cool water.

Itchy Skin  try Kombucha Vinegar instead of Soap simply rub onto skin and forego the irritation of soap

pimples on a cotton ball on your face every night helps prevent pimples and improves skin tone. First wash face thoroughly. Then rinse well with warm water to open pores) apply kombucha, wait a few minutes, hen rinse with cool water to close pores.

As a Douche dilute well aged kombucha at least half with water, more water if there is discomfort. Use at room temperature.

soothing bath For a soothing bath. Combine a cup Kombucha Tea and a small handful of sage, allow to sit for awhile and add to the bath.

Hair Rinse leaves a fresh vibrant feeling. Shampoo, Kombucha, Rinse. Kombucha Tea in the final rinse takes the fizz out of a new permanent and to revive an old one.

Kombucha Cream Blend with Aloe Vera , skin cream and or with a Vitamins Mineral supplement & Vitamin E. Certain natural oils like glycerin will (over time) be broken down by the kombucha as the SCOBY feeds on the natural sugars present. May even form a mushroom in your jar! Suggested Use: For rough or irritated skin, to soften skin, use daily apply liberally and wipe off. Not necessary to rinse but recommended when using the first time. As a Hair Rinse after washing hair apply to wet hair, leave on for a few minutes rinse off.


Add a few ounces into a vase holding fresh flowers and the flowers actually seem to perk up.

compost pour blended KOMBUCHA (with other compost items) around and under flowers and plants Kombucha Compost works very fast. good for acid loving plants like: rhododendrons, azaleas, summer sweet, camellias, acers, pieris, avocado trees, gardenias, hibiscus, tomatoes, peppers ... to many it seems Kombucha has saved ailing plants and trees with a well placed culture. Keeps slugs and snails at bay - seems they won’t cross the KOMBUCHA Snail barrier!

Spices to create a personal healthy vinegar

Sour Kombucha will benefit by aging with oak. This process is an important step in maturing fine wine and the finest vinegar. First clarify your kombucha. Siphon or draw off only the top clear portion of the kombucha, leaving the brown sludge behind. (give the brown sludge (yeasts) to your plants or use in baking) Strain through several layers of cheesecloth. You can also use Bentonite Clay to add health benefits as well as clarifying your kombucha. Oak will mellow and mature. An Oak Cask is excellent for this, or one may simply add some oak spirals which is simply, quick and inexpensive method to greatly improve the flavor.

marinating chicken, shrimp, beef or pork. Use as you would vinegar.

Sprouts Soak sprouts with Kombucha instead of water, When sprouted cut up bits of fresh Kombucha and toss together with peanuts and cashews.

Kombucha Tempura Batter Fry

Dip chunks of Fish and vegetables into two cups of Kombucha and then into a batter made up of equal parts flour and cornmeal, salt and pepper, and a twig or two of dill and fry in olive oil till golden brown. Serve with Sparkling Kombucha

Kombucha Marinate

1 cup Kombucha Tea
1 cup Soy Sauce
1 tablespoon fresh grated ginger
4 to 6 cloves of chopped garlic
1 small onion
Mix the ingredients together and marinate. Keep refrigerated. Use within a few days

Use spices and herbs of your choice. refer to our section on adding herbs for more ideas.

Kombucha crunchy pickles:

use smaller cucumbers.
add a little fresh onion slices
add a hunk of horseradish root 
top the cucumbers with folded horseradish leaves or raspberry leaves

KOMBUCHA Salad dressing

Start with some zesty vinegary Sour Kombucha and to your delight add a clove of Garlic, bright red hot pepper, some oregano, sage, fresh ginger. Olive or Sesame oil. For a creamier texture add mayo.

One favorite vinaigrette is a zesty KOMBUCHA with Tarragon


 2 ounces Aged Kombucha Brew
1 tbsp olive oil
1 tsp freshly squeezed lemon juice
2 cloves fresh garlic, minced
1 pinch favorite seasoning
1 tsp of honey

Grilled Kombucha Marinated Salmon

1 cup Kombucha Tea
1 cup Soy Sauce
1 tablespoon fresh grated ginger
4 to 6 cloves of chopped garlic
1 small onion
Mix the ingredients together and marinate fillets in the refrigerator overnight Grill over hot coals and serve with lemon and orange slices over wild rice.

Kombucha Banana Strawberry Smoothie

10 ounces orange juice
4 ounces Kombucha tea.
One piece of fresh Kombucha colony (sized to palate)
5-6 large fresh strawberries
1-2 large banana
Blend all ingredients at high speed in your blender until smooth

more ideas  Mix with fresh strawberries, blackberries, raspberries, artichokes, for a cool side salad

Green Kombucha take fresh green tomatoes, bell peppers, chilies, cucumbers and cover with Kombucha

KOMBUCHA Dog Biscuits

2 cups whole wheat flour 
1/2 cup corn meal
2 tsp vegetable oil 
1 teaspoon sea salt
1 egg 
3/4 cup Kombucha Tea
add vitamins - minerals - herbs (fresh ground flax seed, or flax seed oil, or similar oil good for the skin and hair)

mix together and shape into doggie bones, add more flour if necessary. Use a fork to put air holes. Bake for 1/2 hour at 350F

Dogs and cats and Tumors

In their book "Kombucha Tea for your Health and Healing", Alick and Mari Bartholomew state ... "Several people have reported to us how their elderly Cats and Dogs have shown a significant improvement in health and vitality after being given Kombucha. Skin has improved and coats have become glossy, in addition to brighter eyes. Other senses had improved with an overall increase in energy.

TUMORS We were told of a Cat 15 years old who had a tumor, and was given 1 teaspoon of Kombucha tea in its water every day. Its energy improved to the point of being quite Kittenish, and its bowel movements returned to normal."


leave Kombucha Tea in a loosely covered bowl and as the liquid evaporates the Kombucha Tea turns to taffy.

- try adding herbs and spices for candy or herbal drops.

What about the Mushroom itself ....

The mushroom itself is cellulose, healthy and edible and very tough. I remember reading that the Russians used to use the mushroom to make shoe leather during the war.

Burns and scrapes apply mushroom directly the young thin ones hold to the contour of the body

Morgellons disease one person reported success

sliced kombucha mushrooms;

Slice or chop and give small pieces directly to dogs, horses

Slice paper thin and prepared like Calamari. similar to tofu, cut up sautéed with veggies and sauce. Add to Soups and Stews.

Sliced Kombucha Mushroom with Hot Peppers and Kombucha Tea - Sizzling


Blended Caution with placing the mushrooms in a blender. You need liquid to avoid burning out your motor.

Blend a Kombucha Mushroom with 2 gherkins, Load lots of Kombucha Vinegar over french fries, and arrange neatly in a small dish, slice of lemon and lime to garnish and voila!, Gherkin Pomme Fritters a La Kombucha.

Kombucha Banana Strawberry Smoothie

10 ounces orange juice
4 ounces Kombucha tea.
One piece of fresh Kombucha colony (sized to palate)
5-6 large fresh strawberries
1-2 large banana
Blend all ingredients at high speed in your blender until smooth,


Dried Kombucha also make a fun and healthier chew toy for furry friends

Kombucha Drum Skin & Leather-Like Stuff

Use the souring kombucha to make a large mushroom and to make a drum skim or other artwork. Add a bit of sugar and tea mix (up to 50%) and place in a large container the size larger than you wish to create. see section below on drying mushrooms.

see also How to make Kombucha Extract, and the Famous D1 Drops

have a favorite recipe let us know and we will list it here as well as your comments and suggestions


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copyright 2006-2008.2016.  all rights reserved Ed Kasper LAc   cell / text  919-518-3336

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