Water Kefir SOS: Troubleshooting Your Brew

Making your own probiotic-rich water kefir can be a rewarding and cost-effective hobby, but as a living culture, it can sometimes throw you a curveball. Room temperature, water quality and inadequate nutrition are just a few factors that can influence the health of your kefir grains and the quality of your water kefir. 

No two batches are the same!

From cloudiness and off-flavors to sluggish, uncooperative grains, you’re almost certain to encounter some of these common challenges at some point along the way…

Cloudiness in water kefir is often due to an excess of yeast.

This can be because of too-warm brewing conditions that throw off the balance of yeast to other bacteria. If your brewing location is on the warm side, consider moving your ferment to a cooler location.

You might also try reducing the fermentation time. The longer you ferment water kefir, the more yeast can multiply, leading to cloudiness. Experiment with shorter fermentation periods until you find the right balance between flavor and clarity.

To reduce yeast, strain the water kefir to separate the grains from the liquid. Rinse the grains thoroughly with non-chlorinated water to remove excess yeast and other residues.

Note that a certain degree of cloudiness can be normal in water kefir due to the presence of live cultures and natural fermentation byproducts. If your cloudy water kefir does not have a yeasty strong odor or off-flavor, the cloudiness may simply be from mineral deposits or undissolved ingredients.

Always trust your senses and do not consume if the kefir has a bad smell or taste.

After the initial ferment, you can choose to drink your water kefir plain OR you can customize it with juice, fruit, herbs and spices. This optional step is known as the ‘second ferment’ and it’s necessary if you want your kefir to be carbonated.

The second fermentation involves transferring the partially fermented water kefir to a new container and adding additional sugars like juice or fruit and sealing it with an airtight lid. Microorganisms present in the water kefir consume the fruit sugars, producing carbon dioxide that builds up and dissolves back into the liquid, resulting in natural carbonation.

If your water kefir still lacks fizz after a second ferment, double check that your bottle/jar has an airtight seal. Without a tight seal, the carbon dioxide will escape, leading to reduced carbonation levels.

Make sure you're using enough sugar (typically 1/4 cup of sugar per quart of water). The beneficial microorganisms in the water kefir grains require sugar to produce carbon dioxide, which creates the fizz. If you're using low-sugar fruits or fruit juice without enough natural sugars, consider supplementing with a small amount of sugar to ensure a sufficient food source for the microorganisms.

Experiment with different fruit juices to find the ones that work best for carbonation. Personally, I've had pretty consistent results whenever I've used pineapple juice. Adding a small piece of candied ginger is also a pretty consistent ticket to fizzy town!

Of course, the fermentation process is also temperature-sensitive. Try doing your second ferment at a slightly warmer temperature, as this can encourage the microorganisms to produce more carbon dioxide. However, avoid excessively high temperatures, as they can lead to over-pressurization and a fizzy mess.

Mold can occur if the fermentation environment becomes contaminated. Mold in water kefir will appear as fuzzy, hairy or powdery growth on the surface of the liquid. It can have various colors, including white, pink, green, blue, black or gray. Harmless Kahm yeast, on the other hand, typically appears as a thin, whitish to cream-colored layer on the surface. It may look wrinkled or bubbly but will not have a fuzzy or hairy appearance like mold.

If you suspect mold in your water kefir, do not consume or attempt to salvage the kefir. Discard the entire batch, clean your equipment thoroughly and start over with fresh kefir grains.

To prevent future mold contamination, make sure that you're maintaining a hygienic fermentation environment. Always use clean utensils and vessels, avoid using chlorinated water and ensure the kefir grains are fully submerged during fermentation.

A creamy-looking white film on the surface of your water kefir is a sign that your brew has captured some wild Kahm yeast. Kahm yeast is typically a thin, whitish-to-cream-colored layer and may appear wrinkled or bubbly. (It will NOT be hairy or fuzzy, which is likely to be mold.) While harmless and not dangerous to consume, Kahm yeast may alter the taste of the water kefir and give it an "off" flavor.

Double check that you're using the correct amount of sugar (typically 1/4 cup of sugar per quart of water). If your water kefir contains too little sugar, there might not be enough food for the beneficial yeast and bacteria, making the environment more favorable for Kahm yeast to take over. 

Higher temperatures can also encourage the growth of wild yeasts, so keep the temperature of your fermenting environment in the 68°F-78°F range. Make sure you're not over-fermenting your water kefir, which can also create favorable conditions for Kahm yeast.

If your kefir has developed Kahm yeast, use a clean spoon or spatula to carefully skim off the yeast from the surface of the water kefir and move on to the secondary fermentation. Kahm is an aerobic yeast, meaning it thrives in the presence of oxygen, so the sealed environment in the secondary fermentation should get the Kahm yeast under control. Fruit or fruit juice in the second ferment can improve the flavor, but depending on the amount of Kahm yeast in the brew, be prepared to discard a batch or two before the kefir's flavor returns to normal.

If your water kefir tastes "off" it might be due to a variety of factors.

An imbalance in the ingredients can lead to the development of wild yeasts (such as Kahm yeast) that may cause unusual flavors. Verify that you're using the correct proportions of water, sugar and water kefir grains in your recipe and that you're not using too much mineral-rich sugar such as sucanat or rapadura. While some minerals are a good thing, over-mineralization can contribute to off-flavors in water kefir, sometimes causing a metallic or bitter taste. (See 'troubleshooting sugar options' below)

Additionally, having an excessive number of water kefir grains relative to the liquid can lead to an imbalance in the microbial population, resulting in undesirable off-flavors. The ideal ratio of water kefir grains to liquid is generally around 1 tablespoon of grains for every 1-2 cups of water.

Higher-than-ideal temperatures may favor the growth of certain microorganisms over others, potentially leading to a shift in the microbial balance within the water kefir grains and changes to the flavor. The recommended range for water kefir fermentation is 68°F to 78°F.

Over-fermentation can also lead to an off-taste. Having too many grains for the amount of liquid and extreme temperatures can both lead to over-fermentation. If your grain-to-water ratio is correct and the temperature is within range, try reducing your fermentation time to see if it improves the flavor.

If you're certain that the culprit isn't mold, sometimes you can salvage an off-tasting batch by moving onto the second ferment stage. The addition of fruit or fruit juice combined with the anaerobic environment of a second ferment can reduce any oxygen-loving wild yeasts that might be contributing to the unpleasant flavor.

It's also not a bad idea to rinse your water kefir grains thoroughly in cool, non-chlorinated water before you use them to start your next fermentation batch.

Healthy water kefir grains should multiply over time. If they're not growing, it could be a sign of stress or inadequate nutrition.

Ensure you are using clean, non-chlorinated water for making water kefir. Chlorine and other chemicals in tap water can harm the kefir grains and inhibit growth. If using tap water, let it sit for 24 hours to allow the chlorine to evaporate.

Verify that you're using the correct amount of sugar (typically 1/4 cup of sugar per quart of water). Kefir grains need sugar as their primary food source. Too little sugar can weaken the grains, affecting their growth. However, more is not always better. Adding sugar beyond the recommended amount can also lead to problems.

Likewise, overcrowding the grains in too little water can also cause stress and they may not multiply as effectively. The ideal ratio of water kefir grains to liquid is generally around 1 tablespoon of grains for every 1-2 cups of water.

Check that the fermentation environment is within the appropriate temperature range (between 68°F to 78°F). Extreme temperatures can stress the kefir grains and impede growth.

Sometimes, the water kefir grains may not be receiving all the necessary nutrients they need to thrive. Refer to 'troubleshooting sugar options' below for a list of ideal (and less-than-ideal) sugar options. You can try adding a small pinch of baking soda or a clean eggshell to the fermentation jar to provide essential minerals.

Healthy water kefir grains should be plump, translucent and have a slightly gelatinous texture. If your water kefir grains are shrinking or deteriorating, it indicates that they may be unhealthy or stressed.

Poor water quality can negatively impact water kefir grains. Make sure you're using clean, filtered water that is free from contaminants and chlorine. If using tap water, let it sit for a few hours to allow any chlorine to dissipate before adding your grains.

Insufficient minerals can lead to grain deterioration. If your water source has low mineral content (e.g. reverse osmosis water), consider adding small amounts of mineral-rich ingredients such as unsulfured molasses, mineral drops or a pinch of natural sea salt to the water kefir solution.

Overcrowding the grains in a small amount of liquid can also cause stress to the grains, affecting their health and vitality. Likewise, ensure that you're using the correct amount of sugar, as insufficient sugar can starve the grains, leading to deterioration. An ideal balance of water kefir grains, sugar and water is generally around 1/4 cup grains + 1/4 cup of sugar + 1 quart of water.

Extreme temperatures can stress the grains. Maintain consistent and appropriate fermentation temperatures between 68°F to 78°F.

Prolonged exposure to direct sunlight can also negatively affect the health of the grains. Direct sunlight can cause the temperature inside the fermentation container to rise higher than the ideal range. UV radiation may also alter the microbial balance in the grains, leading to a decline in their health and fermentation activity. If your fermentation container was in a sunny windowsill, consider moving it to a shaded spot out of direct sunlight.

Healthy water kefir grains are plump, round and have a slightly translucent appearance. The color can vary, but they typically range from off-white to light tan, depending on the type of sugar used as a food source. Color is mostly influenced by what sugar you feed them (brownish sugars = brownish grains). Darker discoloration or brown or black spots may indicate stress or contamination.

Ensure that you are using clean, filtered water free from contaminants and chlorine. If using tap water, let it sit for a few hours to allow any chlorine to dissipate before using. Keep all equipment and utensils used throughout the water kefir-making process clean.

Avoid overfermenting the water kefir. Prolonged fermentation times can stress the grains and result in spottiness or discoloration. Strain the grains from the liquid once the fermentation is complete, usually within 24 to 48 hours.

Make sure you're using the correct amount of sugar in your water kefir recipe (typically 1/4 cup of sugar per quart of water). Too little sugar may starve the grains, while too much sugar can cause stress and imbalances in the fermentation process.

Maintain a consistent and appropriate fermentation temperature. Water kefir grains thrive in a range of temperatures, usually between 68°F to 78°F. Extreme temperatures can stress the grains.

Slight discoloration of water kefir grains is usually harmless and does not necessarily indicate an issue with the grains' health or fermentation performance. As long as the grains demonstrate normal fermentation activity and produce good-quality water kefir, slight discoloration is generally not a cause for concern.

If you prefer to maintain the traditional appearance of water kefir grains or are concerned about discoloration, you can use refined white sugar, which is less likely to cause significant changes in the color of the grains.

If your water kefir is taking an unusually long time to ferment, check the temperature of your fermentation space. Cooler temperatures can slow down the fermentation process. Aim for a moderate temperature range between 68°F to 78°F.

On the other hand, overly-warm temperatures can also cause problems if you end up with Kahm yeast (see 'white film' above), which can compete with the beneficial bacteria and yeast in your water kefir grains, potentially slowing down fermentation and affecting the overall health of the culture.

Ensure you're using fresh, active water kefir grains and non-chlorinated water. Old and/or weakened grains may ferment slower, affecting the overall fermentation process.

If the first fermentation seems sluggish, consider moving on to the second fermentation. Transferring the partially fermented kefir to a sealed container along with some addition sugar or fruit might be the fermentation boost it needs.

If your water kefir turns out too sour, it likely means that the fermentation process has gone on for too long, resulting in excessive production of lactic acid and the strong tart taste that comes along with it. Adjust the fermentation time to achieve the desired level of tartness.

Check the temperature of the fermentation area. Higher temperatures speed up fermentation, while lower temperatures slow it down. Fermenting at a slightly cooler temperature can help prevent excessive sourness.

Using too many grains in a small amount of liquid can also cause rapid fermentation, which can result in an overly sour or alcoholic-tasting water kefir. The ideal ratio of water kefir grains to liquid is generally around 1 tablespoon of grains for every 1-2 cups of water (I aim for 1/4 c of grains per quart).

A second fermentation using sweet fruits or fruit juices can help balance the sourness by introducing natural sweetness and additional complexity to the flavor.

If your water kefir turns out too sweet, it means that the fermentation process has not progressed enough to convert the sugars into acids. The most straightforward solution is to extend the fermentation time a bit longer to allow the kefir grains more time to consume the sugars and produce acids.

Check the temperature of the fermentation area. Lower temperatures slow down fermentation. Fermenting at a slightly warmer temperature can help accelerate the process.

If you've checked these things and your water kefir remains overly sweet after the recommended fermentation time, check the health of your kefir grains. Weak or damaged grains might not ferment efficiently.

If you're using new or rehydrated water kefir grains and they appear otherwise healthy (plump and translucent with have a slightly gelatinous texture), they may simply need some time to adjust and become fully active. Be patient and give them a few fermentation cycles to acclimate to their new environment.

If you've waited for a reasonable period (say, a week or two) and still see little-to-no signs of activity, double-check that you're using the correct ratio of water and sugar and water kefir grains. An imbalanced ratio can hinder fermentation. Aim for 1/4 cup of sugar + 1/4 c water kefir grains + 1 quart of water.

Ensure you're using fresh, non-chlorinated water. If your tap water contains chlorine or chloramine, let it sit out for 24 hours before using it. Alternatively, use filtered or bottled water, as chlorine can harm the kefir grains.

Cloudy, yeasty-smelling water kefir
Troubleshooting sugar options

There are certain types of sugar that you should avoid using, as they can be detrimental to the health of the water kefir grains or negatively impact the fermentation process.

Artificial sweeteners: Avoid using artificial sweeteners like aspartame, sucralose (Splenda) or saccharin. These sweeteners do not provide the necessary nutrients for the water kefir grains and can harm their health (and yours). Just don’t.

Sugars with additives: Avoid using sugars with additives, such as artificial colors, flavors or preservatives. These additives can negatively affect the fermentation process and the health of the water kefir grains.

Honey: While honey is a healthy and natural sweetener, it contains antimicrobial properties that can be harmful to the beneficial bacteria and yeast in the water kefir grains. Using honey can potentially damage or inhibit the fermentation process.

Maple syrup: While maple syrup is a natural sweetener and does contain sugars that can be utilized by kefir grains, it’s not an ideal nutrient balance for optimal fermentation and it can be too mineral rich for water kefir grains To maintain the health and vitality of the water kefir grains, it is best to use only small amounts of maple syrup occasionally and in combination with plain sugar rather than as the sole sweetener.

Molasses with sulfites: Some types of molasses may contain sulfites, which can be harmful to the water kefir grains. Look for unsulfured molasses if you choose to use it to supplement the minerals in your water kefir.

Brown sugar: Darker brown sugars like rapadura and sucanat are less processed and contain much more molasses than white sugar. They can be high in minerals, which may lead to over-mineralization of the water kefir grains if used excessively. It is best to use these sugars in moderation or as occasional variations in the fermentation process.

Coconut and maple sugars: Coconut sugar is derived from the sap of coconut palm trees and maple sugar is derived from the sap of the maple. Both are considered more natural sweeteners, however, like other alternative sweeteners, they can be too mineral rich for water kefir grains. To maintain the health and vitality of the water kefir grains, it is best to use coconut and maple sugars occasionally and in combination with plain sugar rather than as the sole sweetener.

Agave Nectar: Agave nectar is low in nutrients and high in fructose, which can negatively affect the health of the water kefir grains and lead to weak fermentation. (Side note: This may not be a popular opinion, but I consider agave nectar, which contains 70-90% fructose, to be little more than a greenwashed high-fructose corn syrup. I don’t recommend it.)

Stevia, monk fruit (luo han guo), allulose & sugar alcohols: Sugar alcohols such as erythritol and other types of non-nutritive sweeteners are not appropriate for water kefir fermentation, which relies on glucose and fructose to sustain kefir grains’ growth and activity. Using these sugar alternatives alone will not provide the necessary nutrients for the grains. If you wish to experiment with non-nutritive sweeteners, you can try adding them in combination with small amounts of fruit or fruit juice during the second fermentation stage.

Which sugar is best?

Plain ol’ refined white sugar is the most commonly used sugar for water kefir fermentation. While it lacks minerals and other nutrients, refined sugar remains a popular choice for water kefir fermentation because it’s inexpensive and provides the essentials (glucose + fructose) that water kefir grains need for a successful ferment.

Over time, however, using only refined sugar can lead to a deficiency of certain essential minerals in the water kefir grains, and you may find yourself needing to supplement with a mineral source every so often to keep your grains happy. Not a huge deal, just something to be aware of. A smidge of unsulfured molasses, a couple drops of trace minerals or a pinch of mineral-rich sea salt should do the trick.

Alternatively, less processed sugars such as turbinadodemerara or raw sugar* contain small amounts of minerals due to the retained molasses. The mineral content in these sugars is relatively low compared to the darker natural sweeteners like rapadura and sucanat, so there’s less risk of over-mineralization issues. These sugars tend to work well for making water kefir, though you’ll likely end up with darker colored grains, thanks to the molasses content, if that matters to you.

Organic cane sugar, minimally processed and free from chemical additives is my top choice for low-maintenance, healthy water kefir. It seems to be a happy medium between nutrient-void refined white sugar and the darker sugar options. It provides the essential nutrients as well as small amounts of minerals needed by the water kefir grains for optimal fermentation, without being overly mineral rich.

No matter which sugar you choose, look for organic and/or non-GMO, particularly if your sugar is made from beets. In the United States, a significant portion of sugar production comes from genetically modified sugar beets, engineered to resist certain herbicides. Sugarcane is usually still conventionally grown and GMO sugarcane is not (yet) commonplace.

* Technically, demerara should have the lowest molasses content of the three, but the labels “demerara,” “turbinado” and “raw sugar” are often used interchangeably in the real world, so it’s sometimes difficult to know exactly what you’re getting. (Any one of them should work, though!)

Doing a kefir grain reset

Sometimes, despite your best efforts, it’s just not clear what the heck is going on with your wonky water kefir.

In cases like these, I like to do a kefir grain reset.

A reset involves allowing your water kefir grains to go dormant for awhile to rest and recoup. It can help to curb overly yeasty grains, regulate future yeast populations and restore microbial balance. 

Here’s how it’s done:

  1. Remove your water kefir grains from their current liquid and rinse them in cool, non-chlorinated water. Rinsing will help to remove any residual sugars, yeast or other contaminants that might have accumulated.
  2. After rinsing, place the water kefir grains in a CLEAN jar filled with plain water. No sugar should be added at this stage, since you want the grains to rest and recover — not ferment.
  3. Place the jar of grains and water in the fridge to go dormant for one week, changing out the water every few days. Dormancy will allow the grains to recuperate and regain strength.
  4. After the week of dormancy, take the grains out of the fridge and prepare a fresh jar of sugar water to resume the fermentation process as usual. 

After a reset or any period of dormancy, it’s perfectly normal for water kefir grains to take some time to regain their activity. So the first batch after reactivation might not be of the best quality and it’s a common practice to discard this batch. It may take a few batches for the kefir grains to regain their previous vitality.

If all else fails…

If you’ve tried everything, including the reset, and your water kefir grains are still misbehaving, they may be damaged or contaminated beyond recovery. In this case, you might need to replace them with a fresh batch of kefir grains to restore the health of the culture.

Pro tip: If you’ve been keeping your excess grains refrigerated in a water kefir “hotel,” this is a great time to break them out of cryosleep! 


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One Response

  1. I can vouch for water kefir. It’s fizzy like a soda. It tastes good and it’s good for you.

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