Kefir is a fermented milk drink that promotes a healthy gut microbiome. It
contains more beneficial nutrients and bacteria than yoghurt.
Kefir with blueberries and chocolate powder
Milk Kefir is not lactose-free. The fermentation process of milk with Kefir grains reduces the lactose greatly because the Kefir grains feed on the lactose sugar in the milk but the process does not bring the lactose content to zero. People with a mild lactose intolerance can consume Kefir.
Making Kefir, tips
You need about one to two teaspoons of Kefir grains per one cup (250ml) of milk.
This ratio will ferment the milk in about 24h at room temperature (19-25'C). If you take more milk or fewer grains then
the process will just take longer.
The best is full fat organic milk.
This is what Kefir Grains look like
The grains sit initially at the bottom of your jar and rise to the top during the fermentation as the liquid starts to thicken and gases build up. The shape of the jar that you use matters. A wider jar allows you to distribute the grains more evenly over a bigger area. Each grain will have more space and milk around it. This will allow for a maximum efficiency of the process as grains do not compete with each other for nutrients.
If you use a more narrow jar then gently stir every 6-8 hours to allow the milk to fully come into contact with the grains.
If you want to go on vacation then just put the Kefir grains into a big jar with plenty of milk and
store it in the fridge. The colder temperatures in the fridge will slow down the fermentation process.
If the Kefir has the proper growing conditions then you don't have to worry about rinsing the jar
and keeping it clean. The Kefir will completely out-compete any fungus or foreign bacteria. There is no need to wash the jar even if there are spots of dried milk or Kefir near the lid. You can
wash it once a month when too many stains have built up.
Making Kefir every day
Every 24 hours you, strain the fermented milk and Kefir mixture to get the grains back.
Add one cup (250ml) of fresh milk to the
strained grains. You can drink/eat the fermented Kefir milk just naturally or add
something to it. I like to add a few frozen blueberries and a bit of chocolate powder.
Your Kefir grains will grow over time and you can start to use a more coarse strainer which will not
catch all the small baby grains. A more coarse strainer simplifies the straining process.
The proper temperature range for making Kefir is 19-25'C (66'F-77'F). Warmer temperatures accelerate
the fermentation process and lower temperatures slow it down.
The Kefir Grains are damaged at temperatures above 40'C. Kefir grains do survive temperatures
below freezing but after defrosting they will be slow and need some time to recover.
The Kefir Grains become smaller at higher temperature and they grow bigger at
lower temperatures. Grains kept in colder environments will multiply very slowly but reach several inches in diameter.
Kefir adapts over time it's bacterial composition to the environment. This means that the relative ratio of the different bacteria changes. Key factors are:
temperature
oxygen
milk (milk from cows that get antibiotics causes problems)
An almost constant temperature of 22'C, a mostly anaerobic environment and organic milk creates in my opinion the best kefir. You will get a more creamy substance and anaerobic bacteria are more compatible with the environment in your gut.
If your Kefir Grains are slow to ferment and you are just getting a thin and sour milk even after fermenting for longer times then try to find a warmer place. Make sure you fill your jar almost to the top to minimize the amount of oxygen in the jar. Put a lid on the jar and don't fully tighten the lid.
Don't wash the grains with water. Rinsing the Kefir Grains with tap water damages them. They will
however recover as long as you don't do it too often.
If you need to rinse your grains because you dropped them on the floor then rinse them with
milk.
Kefir Grains will multiply and grow under the right conditions and you will eventually have more grains which in turn allows you to add more milk per batch.
The Kefir Grains will completely out-compete any fungus or foreign bacteria. There is no need to wash the jar. You can wash the jar if you find that too many stains have built up but it's not required for a healthy Kefir environment. Just make sure to use good milk and the right conditions to keep the grains happy. They will then take care of the rest. Note however that milk which is already unsafe to consume may not become safe. This is because Kefir will stall the development of e.g listeria bacteria and escherichia coli bacteria but it does not remove them.
During the fermentation process, carbon dioxide will be released. This makes
the kefir a little bubbly and causes it to expand slightly.
Milk Kefir Grains can ferment once in a while nut milk but they will only grow and thrive in dairy milk.
If you keep your kefir in the fridge for a period of time to slow it down, then this does not only slow it down. It changes also the ratio of the different bacteria, which in turn changes the taste and the texture. It will take a few days/cycles to re-balance the kefir after you have taken it out of the fridge. The longer you had it in the fridge the longer it will take to come back. Putting the kefir for few days in the fridge does not change much but keeping it there for a few month changes the bacterial composition completely. The kefir will produce a sour milk instead of a creamy yoghurt like substance even after it's back at room temperature. It will eventually come back and produce again a creamy substance but this takes time. Be patient and keep going.
How to make commercial style kefir? The kefir found in supermarkets is optimized for shelf life and made such that it does not change much over time. It contains fewer vitamins than home style kefir. Some people perfer the supermarket texture and taste. Here is how to make this kind of kefir:
You need a high ratio of kefir grains to milk and you ferment with grains only for a short period of time. In other words you need a large amount of grains.
Put the kefir grains into a jar and barely cover them with milk. Do not add much milk above the level of kefir grains.
Ferment at about 22'C for 4 hours. The resulting substance will still be fairly liquid.
Strain the grains but keep fermenting the kefir milk without grains at 22'C for another 12 hours to a day until it thickens.
Store the resulting kefir milk in the fridge and consume it within a week.
What is this idea of keeping oxygen out? I see many people using open containers or covering their jars with a piece of cloth. You will get some kefir milk either way. You can make kefir in an aerobic or an anaerobic environment however you get a different type of kefir milk. There is no oxygen inside your gut. Most of the bacteria living there are anaerobic. Probiotics that are compatible and beneficial are therefore anaerobic. They thrive in an environment without oxygen. If you fill your jar almost to the top (leave about 1/2 inch of space because the kefir milk expands) then the remaining space will fill with carbon dioxide and push the oxygen out. The kefir will live in a nearly anaerobic environment. This will favor the growth of anaerobic bacteria (e.g bifidobacterium). Kefir grown without oxygen is more creamy. Use a lid on the jar which you don't fully tighten. This allows gas to escape without building pressure in the jar while air circulating in the room will not easily get into the jar. An open jar or a jar covered with a cloth would allow more room air into the jar and favor more aerobic bacteria. Anaerobic bacteria survive the temporary exposure to oxygen when you strain the kefir and they recover until you strain again. Most store bought kefir contains almost no bifidobacterium. They don't try to keep the oxygen out. Note that changing to a more anaerobic process will not have any immediate effects. The kefir will slowly re-balance and you will only notice a difference a few weeks later.
Summary: A wide jar with no lid:
Oxygen loving bacteria are present in higher percentages
More yeast activity, ferments faster
Lid closed and jar filled almost to the top:
Anaerobic bacteria will thrive
Lower yeast content
More compatible with human gut bacteria
The resulting kefir milk is more creamy
I want to try the anaerobic process and I have a 500ml Mason jar but only enough kefir grains for 250ml of milk. What should I do?
Fill your jar almost to the top with milk and ferment for a longer period of time (e.g 2-3 days). Instead of opening the jar and stirring the kefir with a spoon you can fully tighten the lid for a moment and gently shake the jar.
Mailed Kefir problems
The best time to send and order Kefir is March to May and September to November. However any other time of the year can also be OK. Kefir is quite hardy and it just takes a bit of patience to get it back.
Kefir survives freezing. The structure of the Kefir grains does not get damaged when it freezes.
The fermentation speed will be a little slow for a few days but it will come back. If you received a solid block of ice then just thaw it at room temperature and be a bit patient.
What kills kefir is heat. I refrain from sending kefir during the hot summer months. Should a Canada Post vehicle be left parked in the blazing sun then the temperatures inside could easily soar to 50'C or higher, a condition fatal to kefir cultures.
Kefir grains are starving in the mail. The grains are mailed out with fresh milk. They have food for a few days but after that they will be fasting. Long mail transit times (3 to 5 weeks) will stress the grains but they do recover and there is no long term damage.
Things you can do to bring your Kefir back:
During the first few weeks ferment for longer periods (2 to 4 days)
Use the optimal temperature. Try to find a place in your house
that has 22'C (72'F) day and night. An upper shelf board on an inner wall could be a good candidate.
Check your rooms upstairs. Warm air rises and your rooms upstairs could be a degree warmer than
downstairs. Fridges produce constantly heat. Check a shelf board that is above and behind the fridge. Note that temperatures heigher than 22'C (72'F) are not better. I can't explain why but higher temperatures seem to slightly stress the Kefir. Stick to around 22'C (72'F)
Kefir is a symbiosis between yeast and bacteria. Freezing Kefir into a solid block
of ice will have detrimental effects on some of the strains in this symbiotic relationship while others
are not affected.
The Kefir as such will recover and you get some sort of Kefir milk but it can take months until it re-balances. You don't have to do anything if you like it's taste but if you are used to a different Kefir taste then try this: The fastest way to get it back is to add for a few days a spoon full of ready-made supermarket kefir milk when you add fresh milk to your kefir. This will massively accelerate the recovery.
https://www.youtube.com/watch?v=xlZrlm9tsrw, How to make Kefir every day, Kefir 101
https://www.youtube.com/watch?v=aHJpJ23iaSc, How to make Kefir at home