Delicious, fizzy milky goodness. For thousands of years, people have been making and enjoying milk kefir. This healthy fermented drink is easy to make at home and requires no special equipment, just a tablespoon of active milk kefir “grains” and whole cow, sheep, goat, camel or buffalo milk.
What is milk kefir?
It is a drink made by fermenting milk with collections of microbes called kefir “grains”.
The gelatinous grains can range from small irregular lumps to larger cauliflower-like shapes. The outer part of the grain is made up mostly of bacteria, while the centre contains mainly yeasts and funghi. They are all held together in a rubbery polysaccharide matrix (kefiran).
If you have made kombucha, you would have used a SCOBY to ferment sweetened tea. The grains are similar to a kombucha SCOBY – they are both a Symbiotic Community Of Bacteria and Yeasts.
What does milk kefir taste like?
It tastes creamy yet acidic, a little bit funkier than drinking yoghurt. The taste can also vary depending on these factors:
- the origin of the gains
- the type of milk used
- the room temperature at which milk kefir ferments
- the length of time allowed for fermentation
The longer you leave the grains to ferment the milk, the more sugars they eat up and turn into acidic compounds, increasing the tart, sour taste.
What is the origin of milk kefir?
The use of milk kefir grains is traced back to before 2000 BC in the Caucasus, Tibet and Mongolian mountains. Tribes passed grains down from generation to generation as a valuable resource.
Fermenting milk with kefir grains was a way to preserve milk before refrigeration. It also has the bonus of increasing the nutritional value and changing the flavour.
The word kefir derives from the Slavic word “keif” which ” translates as “living well” or “well-be-ing”. This ferment has been associated with health and longevity throughout its long history.
How does fermenting milk change the nutritional profile of milk?
Fermenting milk with kefir grains boosts its nutrition by:
- Breaks down lactose, a type of sugar found in milk that some people are intolerant to.
- Changing the milk proteins into forms that are easier to digest for our bodies, increasing the levels of healthy amino acids (the building blocks of protein), such as lysine, threonine, methionine, and tryptophan
- Increasing levels of vitamins and minerals, including water-soluble B vitamins and fat-soluble vitamins A and K
The Health Benefits of Milk Kefir
Over the last ten years, some scientific studies have started to explore the health effects of milk kefir. The evidence so far gives support for the following health benefits:
- a potential source of probiotics
- reduces symptoms of lactose intolerance
- helps maintain healthy populations of microorganisms in the gut
- potentially aids in lowering cholesterol
- helps regulate blood sugar levels
- potentially aids in maintaining healthy blood pressure
- decrease risk and progression of chronic diseases through anti-inflammatory and anti-oxidative activity
Microorganisms in milk kefir are considered to have probiotic potential and are associated with improved gut health. Also, acids released during fermentation can prevent disease-causing micro-organisms from attaching to the inside of the gut.
Sourcing milk kefir grains: fresh or dried
There should be no problems sourcing grains. They grow quickly; anyone who ferments milk should have an excess supply.
You can also look at your local online marketplaces – there is usually plenty on offer. Alternatively, you can buy grains from a reputable online health food shop specialising in selling cultures like water kefir grains and kombucha SCOBYs.
How to activate dried kefir grains
To send grains through the post, some suppliers dehydrate them. If you are sent dehydrated kefir grains, you will need to activate them in fresh milk.
Start by soaking them overnight at room temperature. Then, every 24 hours, you will need to change the milk until the grains begin to make kefir. It should take approximately 3-7 days for kefir grains to become fully active.
- 1 Tablespoon kefir grains
- 500mL milk [see note]
- Jar to hold at least 500mL
- Lid to fit jar OR a piece of fine woven cloth or kitchen paper with a rubber band to snugly fit the mouth of the jar.
- Strainer, plastic or stainless steel.
- Place milk kefir grains into a jar.
- Pour milk into a jar, allowing for at least 2cm headroom.
- Secure lid or fabric.
- Leave the jar on your kitchen bench to ferment for 18 - 30 hours out of direct sunlight.
- After 18-20 hours have a taste by dipping a clean stainless spoon into the milk kefir [don't double dip]. It should have that funky fermented tang developing. If it is to your taste, you can stop the ferment now or keep going for a stronger ferment.
- When the milk kefir tastes just right, place a strainer over a clean jar and strain the grains from the milk kefir (see video above). To keep the milk kefir flowing through the sieve, you may need to gently agitate the grains in the sieve with a clean stainless steel spoon. Then, place a jar of milk kefir in the fridge, ready for use. It should remain fresh for about two weeks.
- There is no need to rinse the grains. Instead, place them into another clean jar and start the fermentation process again with another 500mL of fresh milk. If your grains are beginning to grow and multiply, you can freeze a batch for security and gift other excess grains to fellow fermenters.
Dairy Milk: you can use all kinds of milk from a lactating mammal - whole cow, sheep, goat, camel or buffalo milk ...
Plant-based milk: you can use plant-based milk; however, the results are not as consistent - soy and coconut milk are more successful choices - see the Troubleshooting section below for more information on plant-based milk.
Covering: you can cover your ferment using a screw lid or tight woven cloth secured with a rubber band. The screw lid will result in fizzier milk kefir as it traps the gases pro
If you find the taste too strong, you can use as little as 1/2 - 1 teaspoon of grains. Alternatively, just decrease the fermentation time until you reach the level of tang you like. As time goes on, you will find that you will probably crave a stronger ferment.
Check out the Troubleshooting section below for more information. If you have further questions, pop them in the comments at the end of the post.
Troubleshooting milk kefir fermentation
You can use any milk from a lactating mammal! The most popular are cow, sheep, goat, camel or buffalo milk.
If UHT milk is your only option, rest assured your kefir grains will happily ferment it. The addition of microbes will actually increase the nutrient value of UHT milk. You should only use UHT milk when fresh milk is not available.
You can use plant-based milk. Full-fat soy and coconut milk are the better choices to create richer, creamier kefir. However, plant milks with low nutrient value will produce thinner kefir, and the taste can be a bit off.
Some sources suggest refreshing your grains in a batch of animal milk once a week. I would stick to kombucha, jun, water kefir and wild sodas rather than retrofitting a ferment that thrives on animal-based lactose instead of plant-based sugars.
Make sure you use the close jar method for fermentation – use a screw-top lid rather than a cloth cover while fermenting [see recipe above]. The longer you ferment it, the fizzier [and sourer] it gets as the fermentation process releases more carbon dioxide.
You can further amp the fizz up with a second fermentation. Once you have fermented your milk, strain the grains, pour the fermented milk into an airtight container, and leave it on the bench for another 24-48 hours. The milk will continue to ferment quietly.
Thickness usually depends on the fat content of your milk. For example, using whole cream milk will generally produce thicker kefir. Also, consider your fermentation time – you may need to increase the fermentation time if you live in a cooler climate and or do a second ferment (mentioned above).
If this happens, you can give it a good stir before straining off the milk and making a new batch.
To stop it from happening again, consider if:
1. You have fermented your milk kefir for longer than usual. Solution: decrease the time you have been fermenting.
2. The environment you are fermenting in might be warmer than usual, or the seasons are changing to warmer. Solution: move your ferment to a cooler area or shorten the fermentation time.
3. You might have grown more grains. Solution: strain your grains and remove excess grains.
You will need to throw out your ferment and source fresh grains. There should be no discolouration or mould on the layer exposed to the air.
Sometimes the top layer can look a little dry, and if you use unhomogenised/fresh milk, the cream at the top can have a healthy tinge of yellow. You can stir this in. If there is any other discolouration or a rank smell – throw it away and source new grains.
I hope you enjoy making this milky ferment as much as I do
Pop into the comments below if you want to share some love for kefir. Any questions? Leave a comment :)