How to Tell If Your Kefir Grains Are Alive

You may be wondering if your milk kefir grains are still alive and whether or not they are safe to use. While kefir grains are perpetual, sometimes our grains get neglected, fermented harshly for years on end and may not perform how we think they should be performing, leading us to wonder “are my kefir grains still alive?”

The good news is that milk kefir grains are remarkably resilient. Even when they have been refrigerated, dried out or left without fresh milk for longer than intended, they can often be revived.

The key is understanding what healthy, active kefir grains should look and behave like.

What do healthy milk kefir grains look like?

Fresh milk kefir grains typically look like small, irregular pieces of cauliflower. These can vary in size from 1mm to 30mm in size and shape. The culture or more often referred to as grains are soft, white and rubbery in texture.

Their appearance can vary depending on the milk they have been fermenting in and how established the culture is.

Importantly, kefir grains don't need to look perfect to be viable. They may be small, lumpy, uneven or slightly yellowish and still be completely healthy.

Yellowish grains are usually this colour from being in cream. 

How do I know if my kefir grains are alive?

The best test is simple: put them in fresh milk and see what happens.

Place your milk kefir grains into fresh milk and leave them at room temperature, ideally around 20–25°C. Depending on how active the grains are, fermentation can take anywhere from approximately 12–24 hours. The warmer it is the faster they ferment. Some grains are also very active and can ferment your milk quickly, despite cooler temperatures. 

Signs that your kefir grains are active include:

• The milk becomes thicker or more viscous.
• The milk develops a pleasantly tangy, fermented aroma.
• The flavour becomes sour or slightly acidic.
• You may see small bubbles or pockets of whey.
• The milk separates into curds and whey if fermentation progresses further.

You don't necessarily need to see dramatic separation for your kefir grains to be viable. Thickening and a characteristic tangy kefir smell are good early indicators that fermentation is occurring.

My kefir grains aren't fermenting milk. Are they dead?

Not necessarily.

Kefir grains can become sluggish after being stored in the refrigerator, transported, dehydrated or left without regular feeding. They may simply need time to become active again.

If your grains aren't doing much during their first fermentation, don't throw them away immediately.

Strain the grains from the milk and place them into a fresh batch of milk. Repeat this process every 24 hours, using fresh milk each time.

It may take several feeding cycles for refrigerated or recently transported grains to return to normal activity.

During this period, the first few batches may smell unusual or ferment very slowly. This does not automatically mean the culture has failed.

How long does it take to revive milk kefir grains?

There isn't one exact timeframe because it depends on how the grains were stored and how long they have been inactive.

Healthy refrigerated grains may become active again within a few days. Grains that have been dormant for considerably longer may require more feeding cycles.

The important thing is to look for progress. If the milk gradually begins thickening and developing the characteristic sour kefir aroma, your grains are becoming active.

If they are taking some time, just ferment 1 cup of milk at a time, so you do not feel like you are wasting milk. If your grains have been dried or dormant for a while, it is advisable to give them a chance for about 7 days. 

When should I discard my kefir grains?

While kefir grains are resilient, there are situations where you should be cautious.

Discard the grains if they develop visible mould, a strong rotten or putrid smell, or other obvious signs of contamination. Don't attempt to rescue visibly mouldy grains.

A slightly sour, yeasty or fermented smell is normal. Kefir is a living culture containing bacteria and yeasts, so it should smell fermented rather than fresh milk.

The simplest viability test

If you're unsure whether your milk kefir grains are alive, don't judge them solely by their appearance.

Feed them.

Put the grains into fresh milk, leave them at a suitable room temperature and observe the milk over the next 12–24 hours. Repeat with fresh milk if necessary. Repeat up to 5-7 times. Alternatively, if you want to avoid the hassle you can purchase new ones. 

If the milk gradually thickens, becomes tangy and shows other signs of fermentation, your kefir grains are viable.

Still not sure?

Grab a fresh lot from our kefir grains which are nurtured daily, here in Papamoa, Tauranga NZ.