Ok here is a slightly edited down version of how to store Kefir Grains for longer periods of time:
STORING KEFIR and REDUCING LACTOSE CONTENT:
If lactose levels are not a problem, and you want a 'sweeter', less sour flavor, then consume kefir as fresh as possible, directly after straining.
Strained Kefir may be stored in the refrigerator in a sealed container, where it should keep for weeks or some months. A portion of kefir may be removed for consumption, then replenishing the container with freshly strained batches.
Storing kefir like this on an ongoing basis, will tend to produce a kefir with extra sourness .
This method is the no-fridge method
Store freshly strained kefir in a sealed container and leave at room temperature to ripen for a few days. Note that this method produces kefir with lots of FIZZ! Freshly strained kefir may be placed in a clean glass jar and stored at room temperature for up to one week or longer in cool climates, or for up to 3 to 4 days in warmer climates.
Pour freshly strained 12 to 24 hour brewed kefir into a glass jar, not filling the bottle more than 3/4 full
Place a tight lid on the jar
*Give the bottle a good shake once or twice daily [to prevent spillage, make sure the lid is tightly fitted before shaking]. Release any CO2 gas buildup by opening the lid, and then tighten the lid once again.
One may pour off amounts of kefir from the bottle daily, until all the kefir is consumed. Alternatively, after removing a portion of kefir, the bottle may be replenished with freshly strained kefir; and then repeating the process daily over 1 week. Then the container is washed clean with hot water and detergent and the process is recommenced.
*The kefir must be shaken 1 - 2 times daily. The reason is to prevent Yeasts and Acetobacter colonies from forming on the surface of the kefir. If not agitated, these colonies may be seen as a light-brown wavy film. Although the initial development of such colonies are not harmful, if left unchecked, unwanted molds may possibly propagate on the colonies; agitation prevents this, possibly due to increasing freely available oxygen.
Due to secondary fermentation, the processes explained above may produce a slightly sourer tasting kefir, with a considerable increase in effervescence.
Although this process will produce a kefir with much less sourness, in comparison to a kefir stored in the refrigerator for the same length of time.
Some of the B group vitamins, particularly Folic acid [Folacin], will increase as the kefir is left to ripen for a few days. Within 48 hours, Folic acid may be expected to increase by at least 116 % in comparison to the original fresh milk or freshly stained kefir. Due to the latter fact, ripened kefir is most favorable taken during pregnancy.
TAKING A BREAK FROM KEFIR
Resting Kefir Grains
If you need to take a break from Kefir for a short period, say between 3 days to 1 month, then there are a few options to take advantage of. This also depends on whether someone is available as a baby-sitter for your kefir grains [during the resting period].
If someone is available to baby-sit, then the first option below may be implemented, otherwise the second option may be followed instead.
1) The BABY SITTING METHOD:
For a resting period of up to one week:
Place the grains in a jar with the same amount of fresh milk that the grains usually ferment
Store in the refrigerator for up to 1 week
Strain the kefir [which is safe to consume]
The grains are now ready to cultured per usual
*[Note that the first few batches prepared after resting the grains, usually take longer to ferment]
This process slows down the metabolism of the micro flora [the organisms go into a semi-dormant state]
Resting kefir grains for longer than one week:
As explained in option 1 above, instead, straining the kefir and adding fresh milk weekly is performed.
This option may be performed for as long as required. When culturing is recommenced at room temperature, the grains will need some days to recover, so the kefir may take a little longer to complete.
Once the grains are removed from the refrigerator, the temperature increase will also increase microbial activity, over a period of time. It may take anywhere between 2 to 7 days for kefir grains to reach optimum activity. The longer the resting period, the longer it will take for the grains to reactivate fully.
2) The NON BABY SITTING METHOD.
Resting kefir gains for longer than one week
As in option 1 above, but increase milk volume by 30-50 % for each additional week of rest [Recommended maximum ratio of no greater than 1:60 grains to milk by volume is preferable].
Resting Kefir grains as above, is safe to do for a periods of up to 2 - 3 months, although you really should use a long term storage method if you go longer than a month and should dehydrated the grains.
NOTES: During the resting process, some species of microbes and yeasts of kefir grains will reduce in numbers. Therefore an adjustment or a recovery period is needed until a balance between the micro floras is once again attained. The longer the grains are kept dormant, the longer the recovery period. In extreme cases, recovery may take up to 2 weeks or longer. During this period, the kefir will produce variations regarding appearance, flavor and texture.
STORING KEFIR GRAINS
Always create a backup source of kefir grains!
Freezing Kefir Grains
One method for storing kefir grains for periods of up to 2 months is by freezing the grains. To freeze kefir grains effectively, wash the grains with pre-boiled, then COOLED water, pat them dry between pre-ironed cooled white towels to remove excess moisture.
Place the grains in a jar or plastic bag; with the addition of dry milk powder [do not add fresh milk or other water based liquids].
Add enough milk powder to completely cover the grains, and then freeze.
The dry milk powder is added as a protective agent.
Although the kefir grains are viable for up to one year when using this method, this length of time may completely remove the yeast component found in healthy kefir grains [when frozen for longer than 2 months].
Because of this, freezing kefir grains as explained above is best performed for a period of no longer than 2 months. If dry milk powder is omitted with the kefir grains, then a period of no longer than 1 month is recommended. Other wise the yeast component of kefir grains may become damaged.
Drying Kefir Grains
Kefir grains may be dehydrated for long term storage [for up to 12 to 18 months].
To dehydrate fresh kefir grains, wash the grains with pre-boiled, then COOLED water. Pat the grains dry by placing them between a pre-ironed and cooled white towel to remove excess moisture.
Place the grains in either a pre ironed white paper bag, or between two sheets of pre ironed white cotton or linen cloth.
Leave to dry in a well ventilated warm spot, until the grains become quite firm and yellow in color. Depending on temperature, humidity and size of the grains, it may take between two to five days for all the grains to completely dehydrate.
Place the dry grains in an airtight jar and store in a cool place e.g., in the refrigerator [do not freeze]. Add a little dry milk powder with dehydrated kefir grains, adding enough milk powder to cover the grains. Dehydrated kefir grains may be stored for up to 1 1/2 years.
Note: It's best to replenish dehydrated grains with freshly dehydrated grains every 6 months. Old dry grains make great treats for both people and pets alike.
It is not imperative to pre-iron any toweling or paper bags used in the process explained above. This is done to reduce the risk of possible contamination.
REACTIVATING "Back Up" KEFIR GRAINS
Reactivating Frozen kefir grains
To reactivate frozen kefir grains, thaw by placing the grains in a glass with cold water for a few minutes. Place the grains into a strainer and wash off any powdered milk that's adhered to the grains with cold water. Presto! They're ready for action and reaction!
Now, add fresh milk to the grains with a ratio of 1 : 3 of grains to milk by volume [say 1/2 cup of milk to 2 Tablespoons of grains]. Strain off the milk every 24 hours, whether or not the milk has coagulated, then place the grains back in the jar with more fresh milk. When full coagulation occurs within 24 hours of fermentation, your kefir grains have reestablished themselves. At this point in time the milk should smell sour but clean, with a possible aroma of fresh yeast. This could take up to one week and in some cases longer.
The quantity of milk may be increased after every other batch until you're happy with the amount of kefir being produced. After an increase in milk volume, do not increase again until the grains are able to ferment the previous increase within 24 hours. This may take between two to seven batches; depending on many factors e.g. how much you increased by, temperature and the activity of the grains themselves.
Reactivating Dehydrated Kefir Grains
First reconstitute dry kefir grains by placing the dry grains in a jar with the addition of a glass of fresh milk.
Activate by renewing the milk daily after straining that batch, whether the milk has coagulated or not. Do not drink this milk until it produces a clean sour aroma. Reconstituting dry grains may take between four days and in some cases up to one and a half weeks to occur.
When the milk starts to coagulate within 24 hours, producing a clean sour aroma, with a hint of fresh yeast, your grains have reactivated and are rearing to go!
NOTES: When activating dehydrated kefir grains, for the first few days the milk will go through some unusual stages, regarding its appearance and aroma. The milk will initially produce a predominance of friendly yeast activity, evident as "froth" or "foam" forming on the surface of the milk.
Yeast activity may reach a peak after three to 5 days, and then begin to subside as consecutive batches are cultured thereafter. As consecutive batches are cultured, the micro flora should find a balance between the bacteria and yeast components, which kefir grains can achieve quite naturally on their own. This may take between one to two weeks.
Growth rate of kefir grains may not be evident, in some cases, until the third week. The grains should become whiter in color after each consecutive batch. Any yellow or yellow-pink-brown grains that don't have an elastic property, should be removed from the batch after the forth week. These are non propagable grains [do not grow], the portion of which is determined by length and storage conditions of dehydrated grains.
Non propagable grains disintegrate, when squeezed between two clean fingers, having the texture similar to a cheddar cheese. Whereas propagable grains are white and elastic with a slightly slimy feel [Kefiran], felt when gently squeezing a grain between two clean fingers.