Milk Kefir Keeps Separating?

So you purchased milk kefir grains. It’s easy to get frustrated and quit when something goes amiss with your milk kefir. Let’s talk about one of the most common issues most people have when fermenting milk kefir.

Far Left: Whey bubbles beginning to form on the bottom. Middle: Partial separation, Whey bubbles throughout. Far Right: Full separation, Curds have completely separated from the whey.

Why does my milk kefir keep separating?

Extended fermentation.

Some folks purposely ferment their kefir until it separates fully. While it’s ok to do so once in a while, it’s hard on the grains to continuously ferment to the point of separation as it starves the grains. The first sign of starvation is that first whey bubble. This is when the kefir should be strained. If you would like to ferment a bit past that, I suggest adding more milk than usual. Be careful though if you add too much milk the kefir can be susceptible to mold as the PH will not drop quick enough. Adding finished kefir to lower the PH may work, however, that also adds more bacteria to feed.

Too many grains and/or not enough milk.

These both go hand in hand. A brew with too many kefir grains or not enough milk make for short work. This will cause separation far earlier than expected. To fix this you can do one of two things.

Remove some grains. You can freeze or dry them as backups. Or blend them into a smoothie for a probiotic punch!

Increase production by not removing grains and adding more milk than usual.

There is a delicate balance between the grain to milk ratio. No two sets of grains are alike so find what works for you and your grains. Milk kefir grains multiply so this should be part of your kefir maintenance so the balance is not disrupted and you end up with inconsistent results.

The environment is too warm.

Milk kefir is a mesophilic culture that ferments at room temperature between 70-78 degrees Fahrenheit. If the temperature is below 70 the grains will be sluggish and temperatures on the higher end of the spectrum the grains will be too active. Keep the temperature in the recommended range.

One last note. While it is ok to stir or rock the jar occasionally to redistribute the bacteria and inoculate milk that hasn’t been colonized by the bacteria, doing this many times during the ferment will also cause it to separate. Stick to rocking the jar or stirring once which is quite sufficient.