Beginner kefir mistakes (and easy fixes)

At the start

1. Judging your grains on the first batch

This is the most common mistake, and the most disheartening. Your grains have spent a few days travelling in a pouch: they need to get used to your water, your sugar and the temperature of your kitchen. A first batch that is flat, barely fizzy or still sweet is normal. What to do: put the grains into sugar water as soon as they arrive, without rinsing them, give them the full 24 hours and start again. It is often on the second or third batch that the fig rises faster and the fine bubbles appear. Water kefir: the first days explains what is normal at this stage.

2. Mixing up water kefir grains and milk kefir grains

Both get called "kefir grains", but they are not the same thing. Water kefir grains are clear, like little lumps of crystallised sugar. Milk kefir grains are white and creamy, shaped like tiny cauliflower florets. Each has its own home: milk grains in milk, water grains in sugar water. Swap them and you starve them. To tell them apart, have a look at What are water kefir grains?

In the jar

3. Swapping sugar for a sweetener

The sugar is not there to sweeten the drink, it feeds the grains. With stevia, a sweetener or a sugar substitute they have nothing to eat and run out of steam within a few batches. Stick to white sugar, cane sugar or a mix of both, about 60 g per litre. Do not worry about the amount: most of it is used up during fermentation, and the finished drink is only lightly sweet.

4. Using the wrong water

UK tap water almost always works, even the hard water of London, the South East and East Anglia: the grains like a bit of mineral content, and soft water from Scotland, Wales or the North West suits them too. Trouble tends to come from water that smells strongly of chlorine, water that has been through a softener, or distilled water, which has too little in it. If yours smells like the swimming pool, leave it in an open jug for a few hours, or boil it and let it cool. Every case, from very hard water to bottled water, is covered in Water and sugar for water kefir.

5. Sealing the jar

During the first fermentation, the jar is covered with a clean tea towel held by an elastic band, so the culture can breathe while dust and fruit flies stay out. The screw-top lid is for the second fermentation, in the bottle. Closed too early, the jar builds up gas for nothing, and the bottle is where you want your bubbles.

6. Adding too much fresh fruit at the start

In the jar, a dried fig and a slice of lemon are enough. A big handful of fresh fruit breaks down, clouds the water and tangles with the grains, which you then have to pick out. Keep the strawberries, raspberries and ginger for the bottle: that is where they give their flavour and their fizz.

Around the jar

7. The wrong spot

A sunny windowsill, the hob or the top of the oven are too hot and too changeable. A utility room, a conservatory or a hallway in winter is too cold. Below 20°C everything slows down and the kefir stays sweet; above 25°C it turns sour quickly. Pick a fixed spot out of direct sun and stick with it. In the colder months, a shelf in the airing cupboard (not pressed against the tank), or a high shelf in a heated room, is often just right, and Fermenting in winter has more ideas.

8. Rinsing the grains every batch, or using rusty metal

Most of the time there is no need to rinse the grains: you strain them and put them straight back into fresh sugar water. An occasional rinse does them no harm, but doing it every time adds nothing. As for utensils, the sieve and spoon can be plastic, wood or stainless steel; just avoid metal that rusts.

In the bottle

9. Filling to the brim, or forgetting the bottle on the worktop

For the second fermentation, leave a few centimetres of air under the stopper and use swing-top bottles in thick glass made for fizzy drinks. Decorative carafes in thin glass are not built for pressure. In warm weather, open the bottle once over the sink after 24 hours, and once the bubbles are there, after 24 to 48 hours, move it to the fridge: left out for days it turns dry and sharp. A good first bottle to practise on is the lemon and ginger water kefir. The right amount of fruit and the timing are in Water kefir second fermentation.

With milk kefir

10. Too many grains for too little milk, or heated milk

The right ratio is 20 g of grains to 1 litre of whole milk, or 10 g to half a litre. Put a lot of grains into a small drop of milk and the kefir splits quickly and turns very sour. There is no need to heat the milk either: milk at room temperature is ideal, and milk straight from the fridge works too, just a bit more slowly. Finally, give the grains fresh milk every day: grains left for days in the same milk on the worktop wear themselves out. The full method is in How to make milk kefir, and the usual hiccups in Milk kefir problems.

Looking after the grains

A bonus: forgetting the grains in the same sugar water

Grains left for days on the worktop in the same, long since exhausted sugar water get hungry, go slimy and lose their sparkle. Life happens, so plan for it: if you will be away or busy, strain the grains, put them into fresh sugar water with the lid on and park them in the fridge. They will wait for up to two weeks, with the water renewed after a week. When you come back, one or two normal batches and they are back on form. Milk kefir grains can rest the same way for a few days in a jar of fresh milk. The full routine, holidays included, is in Caring for water kefir grains.

Above all: do not give up too soon

A batch that is too sour, water kefir that goes a little stringy, a fig that will not rise: these are adjustments, not failures. Change one thing at a time (the spot, the timing, the water) and watch the next batch. You will soon learn what matters in your kitchen. The rarer cases are in Water kefir problems, and if you are still stuck, write to us: we look at your situation personally.

Frequently asked questions

Have you not got your grains yet? Our live water kefir grains arrive in their liquid, with step-by-step instructions, from £11, and our live milk kefir grains from £14; the kefir duo brings the two together and saves you £4. Standard tracked delivery in the UK is £4.90, free from £35, and all prices include VAT. The complete water kefir guide takes it from there.