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 teaspoon 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 ideal temperature 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 if the temperature is
below 0'C or above 40'C. The grains are however fairly hardy and can recover
unless the temperature was very much outside the range from 0'C-40'C (32'F-104'F).
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 temperature range and at higher temperatures, 23'C (74'F) or warmer, it produces eventually a more creamy substance.
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.
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 temperature 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 8-12 hours until it thickens.
Store the resulting kefir milk in the fridge and consume it within a week.
Do I need to cover my kefir jar with a cloth instead of a lid to allow gases to escape? A lid that is not screened on tight is better than a piece of cloth tied to the top of the jar. The reason is this: 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). A lid that is closed but not tightly closed will allow gas to escape without building pressure in the jar while air circulating in the room will not get into the jar. An open jar or a jar with a cloth lid will allow room air to get into the jar. A kefir made with a cloth lid will taste like a kefir and look like kefir but will have very small amounts of anaerobic bacteria (or none). Anaerobic bacteria survive the temporary exposure to oxygen when you strain the kefir and they can then recover until you strain again but this is only the case if you fill the jar almost to the top and you don't use a cloth lid. Store bought kefir contains almost no bifidobacterium. They don't bother fermenting it as anaerobic as possible.
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