Milk kefir too thin or too thick?

How thick should milk kefir be?

There is no right or wrong thickness. Homemade kefir sits somewhere between buttermilk and a thin yoghurt, and it varies from kitchen to kitchen and season to season. Tilt the jar after 24 hours and the kefir should move as one mass, with a clear drop of whey here and there. That is the point at which most people strain.

The four settings

You have four settings to work with. Change only one at a time, so you can see what each one does.

Your kefir is too thin

After 24 hours it is watery, like milk with a sour edge. What helps, roughly in this order:

• Patience with new grains. The first batches are often thin. After three or four it usually sorts itself out.
• Leave it longer. Try 28 or 30 hours, especially in a cool kitchen.
• Move it somewhere warmer. A shelf in or near the airing cupboard, the top of the fridge, or close to a radiator but not on it.
• Use whole milk. Semi-skimmed or UHT milk always gives a thinner kefir. Channel Island (gold top) milk gives the thickest of all.
• Use less milk. For a few days, try 800 ml instead of a litre with your 20 g.
• Let it ripen. Leave the strained kefir in a closed bottle on the worktop for half a day before it goes in the fridge.
• Chill it. Kefir that has spent a night in the fridge is firmer than kefir straight from the sieve.

If it stays thin despite all of this, check that your grains are not shrinking. More on that in Milk kefir problems.

Your kefir is too thick, or has separated

It is as thick as custard, there is a layer of clear whey at the bottom and it tastes sharply sour. Or it is lumpy, with clumps of curd in a thin liquid.

• Strain earlier. Try 18 or 20 hours, especially in summer.
• Find a cooler spot. Away from the sun, the oven and the dishwasher.
• Weigh the grains. As they grow you can easily end up with 30 or 40 g in the jar. Back to 20 g per litre.
• Use more milk. If you have more grains, simply give them more milk.
• Swirl once or twice. Turn the jar gently halfway through. The grains spread out and the kefir sets more evenly.

Separated kefir has not gone off. Shake it in a closed bottle or give it a quick whisk and it is smooth again. Or turn it into something that is meant to be thick.

Lumpy or stringy

Kefir that comes out of the sieve in lumps has usually gone a little too far. Whisk it in the jug for a few seconds or give it a quick blitz in the blender. A slightly stringy kefir is normal with some grains: they produce a little more of the jelly-like material they are made of. If it becomes truly slimy, the balance has been upset, and a few batches of whole milk and a steady rhythm will help.

Deliberately extra thick: strained kefir

For kefir as thick as a soft cheese, let it drain. Line a sieve or colander with a clean tea towel or a piece of muslin, set it over a bowl, pour in the strained kefir and leave it in the fridge for a few hours or overnight. The longer, the thicker.

• After a few hours: thick as Greek-style yoghurt, lovely with fruit and a drizzle of honey.
• After a night: firm and spreadable, like labneh, on wholemeal toast or an oatcake.
• After a day: almost like a fresh cream cheese. Stir in herbs and a pinch of salt.

The full recipe is strained kefir cheese. The whey that drips out is useful in a smoothie or in bread dough. With garlic, salt and grated cucumber, thick kefir also becomes a fresh kefir cucumber dip.

Deliberately thin: for drinking and baking

If you prefer kefir from a glass, strain it a little earlier, use semi-skimmed milk, or loosen it after straining with a splash of cold milk. With cold water, a pinch of salt and a few mint leaves it becomes a thirst-quencher in the style of ayran. Thin kefir is also the best base for a banana kefir smoothie.

For baking, a thin to medium kefir is exactly right. It has the body of buttermilk, so it goes into scones, drop scones and pancakes in the same quantity. If your kefir is on the thick side, loosen it with a splash of milk until it pours like buttermilk.

Thickness through the year

More tips for the cold months are in Fermenting in winter. Which milk gives which thickness is in Which milk for kefir?

Which thickness for which recipe?

Keep a note on the fridge door for a fortnight: date, milk, hours and how thick the kefir was. After two weeks you will know exactly how your kitchen behaves.

Frequently asked questions

No grains yet? Our live milk kefir grains come in 10 g and 20 g, from £14. Everything about your daily batch is in the complete milk kefir guide.