Caring for milk kefir grains

The daily routine

Fresh milk is everything your grains need. Strain, grains back into the jar, fresh milk on top, once a day. The full method is in How to make milk kefir. Beyond that, a handful of habits make all the difference:

• A regular rhythm. Roughly every 24 hours. A few hours either way does not matter.
• A gentle hand. Stir with a wooden or plastic spoon in the sieve. No pressing, no rubbing.
• A steady ratio. 20 g of grains to 1 litre of milk, 10 g to half a litre. Weigh them now and then on the kitchen scales.
• A calm spot. Out of the sun, away from the cooker, at 20 to 25°C.
• No reactive metal. A stainless steel sieve is fine. Avoid aluminium, copper and anything rusty.

To rinse or not to rinse?

Do not rinse. It may be the single most useful thing to know about milk kefir grains. The thin coat of kefir around them helps the next batch get going, and tap water, which is chlorinated right across the UK, sets them back rather than helping. Plenty of beginners rinse out of tidiness and then watch their grains slowly shrink.

If you do want to clean them once in a while, for example because bits of set kefir are stuck between them, swirl them in a bowl with a little fresh, cold milk. Drain, and that is it.

Taking a break

Kefir makers go on holidays too. The fridge is your pause button: in the cold the grains work far more slowly, so a jar of milk lasts them days instead of one.

In the fridge, use a jar with a lid laid loosely on top rather than a tea towel. Otherwise the grains pick up the smells of whatever is beside them, and nobody wants kefir that tastes of last night's onions.

Getting going again after the break

Take the jar out of the fridge and strain off the grains. The milk they waited in is usually thick and quite sour. You can use it in pancake batter or a batch of scones, where its sharpness is welcome, or pour it away if you do not fancy it. Then put the grains into fresh milk at room temperature.

The first batch is often a little thin, or a little yeasty. After one or two normal batches the grains are back in their rhythm. Do not leave them extra long to hurry them up: fresh milk and the usual 24 hours bring them back fastest.

Growth: what to do with the extra

Well-kept grains grow. After a few weeks you may have twice what you started with, and you will notice it in the kefir: it sets faster, splits into curds and whey sooner and tastes sharper. Time for the scales.

• Use more milk. Reckon on 20 g per litre: with 40 g you set 2 litres.
• Take some out. Keep 20 g in the jar and set the rest aside.
• Keep a spare jar. A few grams in fresh milk in the fridge, the milk changed every week. Handy if you want to experiment with another milk.
• Give some away. A small jar of grains in milk is a lovely present for someone who wants to start. Send them the link to the basic method along with it.
• Eat them. The grains are edible, sour and a little chewy. Some people add a few to a smoothie.

Too much kefir is a nice problem to have. There are ideas in Too much kefir?, and one of the tastiest answers is strained kefir cheese on a toasted crumpet.

How to tell your grains are thriving

Your grains show you how they are getting on. Learn the signs and you can adjust things long before anything really goes wrong.

Grains that are out of sorts usually recover with a few batches of whole milk, a steady rhythm and a spot between 20 and 25°C. If the jar smells really wrong, or you see coloured, fluffy patches, go to Milk kefir problems.

What your grains do not like

• Tap water. Rinsing slows them down.
• Heat. Hot milk, or a jar in the sun.
• Going hungry. Days on the worktop without fresh milk.
• Constant changes of milk. Switching every day knocks them out of their rhythm.
• Plant drinks as a regular diet. They do not grow on them. Read Kefir with plant milk first.
• Soap residue. Rinse the jar and the sieve well after washing.

Through the British seasons

In summer, on the few days the kitchen climbs to 26°C or more, your kefir may be set after 16 to 18 hours. Strain earlier, move the jar somewhere cooler such as the hall or the utility room, or simply use a bit more milk.

Winter is the opposite, and in a British house it lasts a while. A kitchen at 16 or 17°C makes the grains sluggish and the kefir stays thin. A shelf in or near the airing cupboard is the classic answer, as long as the jar is not right against the hot water tank, where it gets too hot. The top of the fridge, or near a radiator (not on it), also works. Damp kitchens are fine for kefir, but keep the tea towel clean and dry and change it often. More ideas for the cold months are in Fermenting in winter.

Frequently asked questions

Want to start a second jar, or start afresh? Our live milk kefir grains are available from £14, and everything about milk kefir is gathered in the complete milk kefir guide.