Milk Kefir Grains Troubleshooting FAQ


Q: I misplaced my instructions. Where can I get another copy?

A: Click here to download a copy of our milk kefir instructions.

Q: How long does it take for the milk kefir grains to rehydrate and begin making kefir?

A: Generally the rehydration process takes 4 to 7 days. During that period, the kefir grains will need to be placed in a cup of fresh milk every 24 hours. Within the first few days, an overgrowth of yeast or a layer of froth or foam may form on the surface of the milk. This is normal. Within 4 to 7 days the milk the kefir grains are sitting in during each 24-hour cycle should start to smell sour but clean (not rotten). The smell of fresh yeast is also common. Within 4 to 7 days the milk will begin to thicken within the 24 hour period. (Please note: this time frame assumes the kefir grains are kept at 68° to 78°F; cooler temperatures may require a longer culturing period). Under some circumstances, the kefir grains may take 2 to 4 weeks to start making kefir. Please be patient during the process.

Q: What kind of milk should I use to make kefir?

A: Kefir grains are not too picky in terms of milk and can be used with pasteurized milk or raw milk; homogenized or non-homogenized; whole milk, low-fat or fat-free. We do recommend against using Ultra-Pasteurized (UP or UHT) milk as it has been highly processed and is generally void of bacteria which presents a less than ideal environment for the kefir grains and tends to yield less consistent results. If you choose to use raw milk, please see our instructions on how to transition kefir grains to raw milk.

Q: Can I make kefir with raw milk?

A: Yes, kefir grains can be used with raw milk. There are some specific techniques we recommend for transitioning kefir grains to raw milk. Once they have been transitioned, there are no special instructions for using raw milk; just make kefir as you would using pasteurized milk.

Q: What do I do with the milk used to rehydrate the kefir grains?

A: The cup of milk used each day to rehydrate the kefir grains can be used for cooking provided it looks, smells and tastes okay. Alternatively the milk can be discarded.

Q: How will I know when the kefir grains are making kefir?

A: Once the milk starts to thicken (similar to the consistency of cultured buttermilk or liquid yogurt), the kefir grains are making kefir.

Q: How much space do I need to keep between my kefir and the other cultured foods I'm making (yogurt, kombucha, rising bread dough, etc.)?

A: Kefir has a bad reputation for contaminating other cultured foods (and there are a few cultured foods that are capable of contaminating kefir), therefore we strongly recommend keeping significant space between fermenting and culturing foods (including rising bread dough made with commercial yeast). At a minimum, keep several feet between cultures and preferably more space. Ideally cultures should be kept on opposite sides of the kitchen or in different rooms.

Q: What's the easiest way to remove the kefir grains from the finished kefir?

A: There are several options for removing kefir grains from finished kefir:

  • Use a fine mesh strainer. Plastic strainers are preferable although stainless steel can be used if necessary (avoid all other metals). It is important the strainer be made of a very fine mesh as it's easy for tiny kefir grains to escape. If the kefir doesn't move easily through the strainer, try gently moving it around with your fingers to work it though the strainer. This process also works well for homogenizing kefir if portions of the kefir have started to coagulate.
  • Use a cotton bag. Cotton muslin bags, such as the type health food stores often sell as reusable tea bags, can be used to contain the kefir grains. If using this method it is very important to ensure the bag stays submerged in milk as the bag will attract mold.
  • Use your fingers. As the kefir grains grow, it is often easiest to just fish them out with your hands. Be sure to wash and rinse your hands well as both foreign bacteria and soap can be detrimental to kefir grains.

Q: Can I use a metal strainer with my kefir grains?

A: While plastic is preferred, stainless steel is acceptable. Avoid all other types of metal when working with kefir grains.

Q: Some of the kefir sticks to my kefir grains. Is that okay?

A: Kefir sticking to the grains is normal and does not present a problem. Just remove large quantities and don't worry about smaller layers of kefir that remain on the kefir grains as they go into fresh milk.

Q: Do I need to rinse my kefir grains in between batches?

A: No, it is not necessary to rinse kefir grains between batches unless you suspect they have been contaminated. Kefir grains often work better if they are not rinsed.

Q: My kefir smells like yeast. Is that normal?

A: Kefir will often smell like fresh yeast. If your kefir smells like spoiled yeast (rotten), that can be a sign of either contamination or that the yeast and bacteria which comprise the kefir grains is out of balance.

Q: My kefir is thick and coagulated. How do I find my kefir grains?

A: The easiest way to find the kefir grains is to first stir the kefir well with a wooden or plastic spoon, to homogenize the kefir and break up the coagulated portions. Next, pour the kefir though a fine mesh strainer and gently work the kefir through using your fingers. (Be sure your hands are washed and rinsed well as both foreign bacteria and soap residue can wreak havoc on kefir grains.) This process should allow you to locate the kefir grains as well as homogenize the kefir.

Q: My kefir separated into curds and whey (solid on top, kefir underneath). Can I still use it? How do I keep that from happening?

A: During the culturing process, kefir will generally go through three stages: liquid milk, thickened liquid (generally the consistency of cultured buttermilk or liquid yogurt), thicker kefir (almost a yogurt consistency in some cases), and finally separated into curds and whey. How quickly the kefir moves through the various stages is a function of several factors including room temperature and the ratio of kefir grains to milk. Kefir that has separated is simply kefir that has over-cultured. It is generally safe to consume over-cutlured kefir provided it looks, tastes, and smells okay.  However, over-cultured kefir may not taste terribly pleasant and tends to have a carbonated texture. Over-cultured kefir can also be used for cooking if the taste isn't desirable to consume by itself. 

To prevent the kefir from separating in the future, it is necessary to change one of the key variables: the amount of time the kefir cultures (this is usually the easiest to change), the temperature at which the kefir is culturing (move it someplace cooler), or the ratio between the kefir grains and the milk (use fewer kefir grains). For example, if you use the same temperature and the same kefir grain-to-milk ratio, just reduce the amount of time the kefir cultures: try to catch it when it's in the thickened liquid stage as that tends to be the most pleasant-tasting kefir. If necessary, try starting a batch of kefir in the evening. The next day, check the kefir at the 12-hour mark, and even give it a quick stir to check the consistency. If it's still liquid milk, leave it for a few hours and check again.  Repeat the process until you catch the kefir at the desired stage.

Q: When will my kefir grains start to grow?

A: Kefir grains will often start to grow 6 to 8 weeks after being rehydrated. Once they do start growing though, growth can be slow (not nearly as fast as water kefir grains). Please note: we cannot guarantee that kefir grains will grow or multiply as there are simply too many factors which influence that process. Rest assured, however, that even if the kefir grains do not grow or multiply, they can be used repeatedly to make batch after batch of milk kefir.

Q: What role does room temperature play when making kefir?

A: Warmer temperatures will speed up the kefir making process while cooler temperatures will slow it down. We recommend culturing your kefir at 68° to 78°F.

Q: My kefir is forming very quickly. How can I slow it down?

A: There are two factors that determine how quickly kefir forms: room temperature and the ratio of kefir grains to milk. A warmer room will result in kefir forming faster. A cooler room will slow the process down. More kefir grains (for a given quantity of milk) will form kefir faster than a smaller portion of grains. To slow down kefir production, either lower the temperature at which the kefir is culturing or use a smaller amount of kefir grains. Please note: it is important for the health of the kefir grains that kefir form within 48 hours so please do not try to slow down the process further.

Q: My kefir is forming very slowly. How can I speed it up?

A: There are two factors that determine how quickly kefir forms: room temperature and the ratio of kefir grains to milk. A warmer room will result in kefir forming faster. A cooler room will slow the process down. More kefir grains (for a given quantity of milk) will form kefir faster than a smaller portion of grains. To speed up kefir production, either raise the temperature at which the kefir is culturing or use a smaller amount of milk for the portion of kefir grains you are using. Please note: it is important that kefir not form more quickly than 12 hours (and preferably 14 to 16 hours) so please do not try to speed up the process further.

Q: My kefir has had a consistent taste for several months but the last few batches taste different. What can I do?

A: The taste of kefir will often change depending on how quickly it is culturing. How quickly the kefir cultures is generally dependent on the temperature of the room and the ratio of kefir grains to milk. As the seasons change, it's not unusal for kefir to speed up or slow down its culturing process which can mean the kefir tastes differently when cultured for the normal time period. An adjustment to the amount of time may be necessary. Alternatively, the ratio of kefir grains to milk can also affect the taste. If your kefir grains are growing or you are using less milk than usual, an adjustment may be needed to bring the kefir back to the taste you are accustomed to.

Q: My kefir grains were working but the last batch didn't thicken at all. What went wrong?

A: The most common reason for kefir grains to suddenly stop working as usual is a shift in temperature. Kefir grains operate best at room temperature. If the spot where you are keeping your kefir grains has suddenly become cooler (change in weather, draft from an air conditioner, unusually cold night, etc.), the process can slow drastically and kefir may not form in the normal time period. When this happens, it is best to discard the milk and immediately put the kefir grains in fresh milk and in a warmer spot. If you want to keep the kefir grains in the same milk and simply move them to a warmer location, please use caution. The danger with kefir culturing at too low a temperature is that the yeast and bacteria in the kefir grains have been slowed down by the cooler temperature, but unless the temperature is very cold (similar to a refrigerator), the bacteria in the milk is likely multiplying quickly without the full power of the kefir grains to keep it in check. Under these conditions the bacteria in the milk can wreak havoc on the kefir grains and/or cause the milk/kefir to spoil. 

Q: Can I make kefir only once a week and keep the kefir grains in the refrigerator on the other days?

A: While it is tempting to reduce the amount of care kefir grains need by limiting how often you use them to make kefir, we strongly recommend against keeping your kefir grains in the refrigerator on a regular basis. Cold temperatures slow the kefir grains down putting them into a state of hibernation. Over time, it is very hard on kefir grains to regularly be put into and then come out of a state of hibernation. Keeping your kefir grains in the refrigerator regularly can disrupt the yeast/bacteria balance necessary for the kefir grains to function properly make the kefir grains less efficient and reliable. If caring for kefir grains every day or every other day isn't an option, we suggest using a powdered kefir starter culture rather than kefir grains to make kefir. Each package of powdered kefir starter can be recultured a few times by taking a small amount from the current batch and adding it to fresh milk to make the next batch (must make a new batch at least once a week). This product requires significantly less maintenance than kefir grains and more information on the powdered kefir starter culture can be viewed here.

Q: I forgot my kefir culturing on the counter for several days. The milk has separated and smells funny. Are the kefir grains okay?

A: The biggest danger with leaving the kefir grains in the same milk for more than 48 hours is that they may begin to starve which damages the kefir grains. Be sure to check the top of the kefir for any signs of mold. If none is present, remove the kefir grains from the kefir and place them in fresh milk. Watch the next several batches of kefir carefully to ensure that they are reliably forming kefir and that no mold develops. 

Q: How do I store my kefir grains when they aren't being used (e.g., going on vacation, taking a break from kefir, etc.)?

A: Click here for information on how to take a break from making kefir (without damaging your kefir grains).

Q: I left my kefir grains culturing on my oven and the oven was accidentally turned on so the kefir grains got very hot. Are they dead?

A: While kefir grains are very resilient, excessive heat is one thing that can kill them. If the kefir grains were in a hydrated/functioning state and were exposed to a temperture over 100°F, it is unlikely they survived. If there is any doubt, we do recommend placing them in fresh milk and watching them carefully over the next 24 hours. If kefir forms, they are still functioning. If the milk separates into curds and whey without kefir first forming, then the culture isn't functioning (and the milk is behaving as it would if no culture was present).

Q: My kefir grains have multiplied and I'd like to save some as a backup. Can I freeze them? Dry them?

A: Kefir grains can be stored long-term by drying them. Simply rinse the kefir grains with filtered water to remove all milk residue. Lay them on a piece of unbleached parchment paper and set them in a safe place. Kefir grains will generally dry in 2 to 5 days depending on room temperature and humidity levels. Once the kefir grains are completely dry, they can be stored in a zipper-style bag in a cook dry place or the refrigerator. If possible, package the dried grains with a small amount of dried milk powder. In this state, kefir grains will generally survive at least 12 months.

Q: My kefir grains are multiplying. What can I do with the extras?

A: Kefir grains make a wonderful gift to friends but if you have run out of people to share them with, many people find eating kefir grains to be beneficial (either eating the grains by themselves or blending them into smoothies).

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