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Milk Kefir FAQ: Upkeep & Contamination

 

Milk Kefir FAQ's 

Part 7 - Upkeep & Contamination

Questions in this Section:

Do kefir grains need to be fed every day?
Do you have to wash or rinse your grains?
What if I forgot to strain my kefir when it was ready?
What if I forget about my kefir and its really old?
What should kefir grains look like?
How fast do kefir grains grow?
Should kefir grains float?
Do kefir grains change shape?
What causes grains to change appearance or shape?
Why do my kefir grains look like ribbons?
Why is my kefir grainy, gritty, lumpy, thin or watery?
What are the tiny sticky threads between my kefir grains?
What is the white fuzzy or brown film on my kefir?
What is the orange or hard crust discoloration on the surface of kefir grains?
How do you know if the grains are 'healthy'?
How do you know if its contaminated?
What if I suspect my kefir has been cross-contaminated by another culture?
What are the seasonal differences in Kefir (summer vs winter, etc)?

 Do kefir grains need to be fed every day?

The short answer is yes. Kefir grains need to be strained every 24 hours (or 48 at the max) and given fresh milk. The exception to this is if you ferment directly out of the fridge which takes about a week. It's not that common to ferment directly out of the fridge, but it can make a more bacteria rich kefir (more sour and less fizzy). If you or your grains would like to take a break, stick them in the fridge, refreshing them weekly with new milk. This can be done for a couple weeks, then they should be brought back out to room temperature. If you need a longer break, view our section on storage. Some people ferment directly out of the fridge

Do you have to wash or rinse your grains?

Some people like to do this, but it was never done traditionally and is not necessary at all. By nature, they are a symbiotic mass of microflora that has self-inoculating properties, protecting itself from foreign bacteria or yeast. The lactic and acetic acids it excretes also protects it from becoming contaminated. Many have observed that when they stopped rinsing their grains, they grew better and produced better kefir. Sometimes they can get fat deposit (crusty, orange colored areas) that may indicate they need a gentle scrub and rinse though. If you wish to rinse them, make sure it is clean, non-chlorinated water. Simply run them under flowing water or swish them around in a bowl of clean water, and pat dry.

What if I forgot to strain my kefir when it was ready?

Kefir is very forgiving. Strain when you remember, and feed them normally. They may be extra happy and eat through the new milk quickly, so keep an eye on them and strain when it looks ready (whether its before or after the 24 hour mark). If its been more than a week they may need some time to re-balance, and you may want to wait to consume the kefir until after a couple of cycles/batches.

What if I forget about my kefir and its really old?

Kefir keeps a LONG time, like wine. It may even smell just like wine (or pickles). Sometimes you can revive neglected or forgotten grains. Simply seperate them from the milk in a strainer, give them a rinse with some clean cold, preferably non-chlorinated water, and put them in a little new milk. They most likely won't be that active, so a little milk is enough, you don't want to waste a ton of milk until you see signs of activity. If they seem to process the milk into kefir, then they may be viable to use - keep feeding and wait atleast a few days before consuming, to ensure the drink is more balanced. As with all things, use your best judgement and common sense, if it smells badly or looks off, toss it and secure some fresh new grains from your back-up storage or a friend.

What should Kefir Grains look like?

Kefir grains look a lot like little cauliflower florets. Up close, their pattern is somewhat like coral, or a brain. They can also look like smooth, flat shreds of ribbons during the warmer months (or when crowded in a jar).Their color ranges from creamy off-white to white. They are soft, bouncy and squishy, like a tiny squeeze toy. Dried kefir grains color is usually like a light cheddar cheese, becoming darker (deeper orange) as it gets drier and ages.

How fast do kefir grains grow?

Although not nearly as fast as water kefir, milk kefir grains do grow and you will soon have much more than you started with. They typically grow about 5% during the winter or under cooler conditions and 10% to 25% during summer or under optimal warm conditions. It is also interesting that smaller grains will reproduce much more rapidly than larger grains (this is because there is a greater surface area that can grab nutrients from the milk).

Should kefir grains float?

Yes, sometimes. Most kefir grains encapsulate some of the carbon dioxide gas that the yeasts give off while fermenting. Also, some grains have less density than the milk, and simply float. Some will be dense enough though (and manage to avoid capturing bubbles) that they sink. If you are using dried milk powder, and all the grains are at the top, simply add some more water to increase the density which will allow the grains to relax a bit. Sometimes grains that have been subjected to severe freezer burn, high heat or their outer layer is too encrusted and hard from being dried (or old), also float (and they may not be able to be revived). In this case these grains will usually have a darker color and less soft and sponge-like texture. It is best to see if these are able to propagate new grains (though they themselves may not recover) or toss them if no growth or kefiring is achievable with them. If they reproduce new grains, then you can toss them once you have enough of the new grains (you will be able to still visibly tell which ones are the old, darker ones to be tossed).

Do Kefir Grains change shape?

Yes, they actually go through seasonal changes just like a plant would. This is in response to the weather, temperature, amount of daylight being most likely a combination of all three. In the summer, kefir grains can become more 'relaxed' and stretch out a bit, seeming more limp and spiral-shaped. In response to very hot weather we have found that they can stretch out even more, looking like flat smooth shreds of ribbons. This can also happen when there is overcrowding in the jar or not enough fat in the milk. In the fall (or cooler environment) you will see them start to coil up again into a more tightly wound brain-like patterned balls (or cauliflower florets) for the winter.

What causes grains to change appearance or shape?

A change in temperature, season, milk brand or %, space/milk quantity or bacteria and yeast balance can all affect grain appearance and shape. Pressing or squishing them (or blending them) can also change their appearance for awhile. Because of different proteins, fat amounts or minerals available in different milk %'s or brands, grains can change appearance or shape. Changing temperatures can also dramatically change the shape of kefir grains. Also, the amount of milk available will have an affect (more milk being desirable) on the grains. Grains put under ideal conditions will eventually return to their normal more rounded shape.

Why do my Kefir Grains look like ribbons?

In response to very hot weather we have found that they can stretch out, looking like shreds of ribbons. This can also happen when there is overcrowding in the jar or not enough fat in the milk, squishing or pressing the grains (or blending them) or a combination of all 4 of these factors. Our hypothesis is that they are just adapting to a more rapidly depleted food source, and stretching themselves to look for more nutrients. This does not mean they are unhealthy, it is simply their way of adapting to reach more food. Sometimes it simply seems to be a response to warmer weather and they are slightly more 'relaxed', and then binding and coiling upon themselves more in the colder weather. You can try giving it more milk, a less crowded environment (take out some of the grains) or a cooler area to ferment and they will usually return to forming a more coiled shape again. When straining, try not to squish or squeeze the grains with your hands or spoon.

Why is my kefir grainy, gritty, lumpy, thin or watery?

Kefir can become agitated by a new environment. This can be anything from a seasonal change, climate change, temperature change, milk change, or ratio of grains to milk change for example. Kefir grains like a stable environment with minimal and gradual temperature changes. If it's experiencing variable temperatures (such as spring or fall) where one day is hot and the next cool then it may be grainy or thin. This can also be the case if the night and day temperatures are drastically different. When the night is much cooler than the day such as in fall or spring (or a desert climate), the temperature will alter the acidic curds into a more gritty texture. If the grains do not seem to adjust and return to producing a normal kefir, than the environment may need to be adjusted. In most cases it is due to either being too cold (below 70°F / 21°C), too hot (above 76°F / 24°C - or too many grains making for too quick of a ferment) or due to changing to a milk other than cows milk, a lowfat/nonfat milk, UHT milk, or lactose-free milk (which you should not use). If you are trying to convert your grains to kefir a milk other than cow or goat, than give it a little time and patience for the grains to adjust to their new medium. Also keep in mind that kefir in the summer is generally thinner and in the winter thicker. Because there are so many strains of bacteria and yeast in kefir, different temperatures and contents in the milk can make one strain respond and become more or less active, thus resulting in a slight variation to your finished kefir. This is not something to be worried about, it is just a natural adaptation and response by the grains themselves, as they are designed to do.

What are the tiny sticky threads between my kefir grains?

When you move kefir grains apart from one another you may notice some sticky thread-like strings hanging and stretching between them (think pulling a pizza slice and its dangling cheese strings). It will look like fine thread-like spider web material stretching and sticking when the grains are separated from one another. This is actually a great sign that your grains are healthy and growing. Absence of these threads is ok too - a lack of these does not mean anything bad! These threads are simply known as kefiran by the kefir community and they are a gel forming soluble polysaccharide. You may notice even more during the summer, or if you're trying a new milk. These will often change over time and from season to season, coming and going. This polysaccharide is part of what makes kefir creamy. It is similar to the same compounds found in starch, cellulose, gum and glycogen. Bacteria, fungi and algae have all adopted an ability to produce this as a form of protection from drying out, reproducing and adhering to their food source more efficiently. This promotes viscosity in the kefir and is also soothing to the digestive system (aloe vera juice and gel contains copious amounts of polysaccharides).

What is the white fuzzy or brown film on my kefir?

Although this is not desirable, it is not dangerous. This is simply a Mycodermia - basically a fungi skin (created by yeast and bacteria within the kefir). This is typically found on the surface of wine that has been exposed to too much warmth and air, and is referred to as 'Flowers of Wine'. Because of this, many people now refer to the same phenomenon in kefir as 'Flowers of Kefir'. This film is non-pathogenic and regarded as generally safe. Technically speaking it is yeast forming certain pseudo-mycelium which mimics the look of fuzzy mold (but it's not mold). It usually happens as a result of one or a combination of the following: higher temperatures or tropical climates, too many grains in too little milk (which will increase the activity of the yeast), lack of regular milk changes and/or letting the kefir constantly over-ferment before changing it to new milk. Sometimes it will form on ripening kefir. In this case, you can help discourage the mycodermia from forming by putting an airlock on the lid since the mycodermia thrives on oxygen. If you are up to it, some people even skim this film off their kefir to use as a leavener in breads, since it is safe and edible and provides a great active riser for a sourdough-like bread.

What is the orange or hard crust discoloration on the surface of kefir grains?

Kefir grains can sometimes get encrusted by the fat of the milk. This can happen when the milk is not changed regularly, or if you have been using your grains in cream to ferment sour cream etc. It can also be a result of drying out too much. Dried kefir grains can appear to have this because their outer layer was the most exposed during drying. Using non-homogenized milk (cream floats to the top) can also expose the grains to excess fat, especially if they are not stirred back into the milk once in awhile during the fermenting process. Once they start to grow, this will slowly disappear. In all these cases it is best to place your grains in a bowl of fresh cool water (or kefir) and gently rub them free of their crust with your fingers. You can also toss them in a blender to open them up and expose fresh, un-crusted sides (which will grow better and produce a better kefir). Resume fermenting, with regular milk changes.

How do you know if its contaminated?

It's very difficult to have truly contaminated kefir due to the very nature of the billions of cultures in contains. If however it is contaminated, it will be an off color and/or off smell and you will be able to recognize this. In most cases it will just be a fuzzy spoilage mold of some sort (the same stuff that grows on everything else that spoils). Milk that is already near spoiling or spoiled will usually not produce a good kefir. Also, fermenting too little grains in a near-spoiling milk may encourage the bad bacteria to compete and out-do the small amount of grains (and too warm of a room will encourage this further). As long as you are using clean utensils, washing your hands, keeping the room temperature reasonable and maintaining reasonably clean jars (its ok to re-use them for a few weeks before washing), and covering the jars properly there is little risk of contamination.

How do you know if the grains are 'healthy'?

Kefir grains are very resilient and will strive to maintain their health at all times. As long as your grains are converting milk to kefir that is not 'off' they are just fine. They may get stressed and change shape or smell a bit (more yeasty or more stringy looking), but they will bounce right back given the right conditions. They range from creamy white to a dark ivory and coiled brain-patterned balls to bumpy ribbons. Even when they are not growing they can still produce a healthy drinkable kefir (such as in soy or almond milk), though its best to give them optimal conditions so they can grow.

What if I suspect my Kefir has been cross-contaminated by another culture?

This can occasionally happen, especially with viili culture, which happily mingles with kefir (producing a thicker, creamier kefir). This could be seen as a positive change, but if you do not want these to cross-contaminate, you must ensure that all supplies are used strictly for kefir, or at the least thoroughly cleansed (and rinsed of all soap residues too) between each use. If your kefir has been cross-contaminated, strain the grains from the milk, rinse them very thoroughly under clean, cold, preferably non-chlorinated water, rubbing them gently between your fingers to get all outer residue off the grains. At this point you can place them in a water fast for 24-28 hours (just put the grains in clean, cold water) in the fridge. Strain them, give them another rinse, and resume fermenting in milk. This process may need to be done a couple or more times before all signs of cross-contamination are gone (and to ensure they don't return).

What are the seasonal differences in Kefir (summer vs winter, etc)?

Kefir, like all living organisms, goes through intricate and subtle changes with the seasons, climate, temperatures and environment it is in. Just like you can mark the seasons with a tree budding, growing, turning colors and discarding its leaves, kefir also will constantly be in flux and going through seasonal patterns. Kefir will ferment much more quickly in the summer and warmer temperatures. It will be thinner and may be more lumpy or inconsistent as well. It may especially be inconsistent during spring and fall, or whenever there is a large disparity of temperatures (such as a cold night and hot day). Kefir will tend to be more creamy and mild in the winter and cooler temperatures (and more zesty and sour in the summer). Part of the beauty of the symbiotic nature of kefir is that each strain has a certain strength and weakness. Together, they are able to ferment at a wide range of temperatures. Keeping this in miind, you will realize that because of this, a certain temperature will allow some strains to perform much better, while others may be temporarily suppressed. This contributes to the differing tastes and textures of kefir throughout the year. Some people notice it is more cheesy in the winter (possibly due to the certain yeast and other strains being stronger), while in the summer it may be more bread-ish and light in flavor.