How do you store water kefir grains long term?

Water kefir grains need to be handled carefully to maintain their health and longevity. There are a few key strategies for successfully storing water kefir grains for extended periods of time.

Use the Refrigerator

The refrigerator is the best place to store water kefir grains short-term. At cool temperatures between 35-45°F, the grains will become dormant and stop fermenting. This slows down their activity so they don’t need to be fed as frequently.

To store in the refrigerator, strain finished kefir from the grains. Rinse the grains with fresh, non-chlorinated water. Place the clean grains in a jar and cover with fresh sugar water or milk. Store in the refrigerator for up to 1 month, changing the liquid every 1-2 weeks.

Freeze Them

For long-term storage, the freezer is ideal for preserving water kefir grains. At freezing temperatures, all microbial activity halts. This puts the grains in hibernation so they can be stored for extended periods.

To freeze, start with clean, active grains. Strain out any fermented kefir liquid. Rinse the grains and then let them air dry completely. Spread them out on a paper towel or baking sheet so they are not touching.

Once dry, put the grains in an airtight container or freezer bag. Squeeze out excess air and seal. Label with the date. Frozen grains can keep for 6-12 months.

Use a Sugar Water Solution

Another option for storage is submerging grains in a sugar water solution. The sugar provides food to keep the grains active but the cool temperature in the refrigerator slows fermentation way down.

Make a solution of 1 cup water and 1-2 tablespoons of white sugar or molasses. Put the drained grains in a jar and cover with the sugar solution. Store in the refrigerator and change the liquid every 4-6 weeks as needed.

Dry Them Out

Drying the grains out entirely creates a dormant state for long-term viability. This mimics the natural dehydration process if grains were left out of water.

Rinse active grains free of kefir. Spread them out on a clean paper towel or coffee filter. Allow to air dry for 24-48 hours, flipping halfway through. When completely dry, store in an airtight container in the freezer.

Use Vacuum Sealed Bags

Vacuum sealing is an easy storage technique. Rinse the grains and let dry completely. Place them in a vacuum bag and suck out the excess air before sealing. Store in the refrigerator or freezer.

The lack of oxygen slows fermentation to a near halt. Vacuum sealed grains can last up to 6 months in the freezer.

Store in Sand

Some kefir brewers have success storing grains mixed in with sterile, dried sand. The sand must be completely dry with no moisture. It provides a stable environment to suspend the grains’ activity.

Bury dried grains in dry sand in an airtight container. Store in a cool, dark place like a pantry. Change the sand every 2-3 months. With proper sanitation, sand storage can last over a year.

Use Food-Grade Diatomaceous Earth

Food-grade diatomaceous earth (DE) is a very fine, chalky powder that can help store grains. The powder absorb moisture and maintains a stable humidity.

Make sure the food-grade DE is safe for consumption. Mix in dried grains so they are fully coated. Store in an airtight container in a cool, dry place for up to a year.

Keep Them Cool

The overall rule for long-term storage is to keep water kefir grains as cool as possible without freezing. Refrigerator temperatures of 35-45°F are ideal for maintaining dormancy.

Even at room temperature, grains will need to be fed every 2 weeks or so. The warmer it is, the faster fermentation happens and the sooner they will need fresh sugar water or milk.

For periods over a month, definitely refrigerate or freeze the grains. Monitor stored grains occasionally for any signs of degradation or mold.

Use An Anti-Fungal Solution

An anti-fungal solution can help prevent contamination during storage. Make a solution of cooled boiled water with a pinch of salt and few drops of lemon juice. Soak the grains to kill off any yeasts or molds.

Rinse the anti-fungal solution off fully before refrigerating or freezing the grains. The solution creates a clean slate to limit the chance of spoilage.

Store in Milk

Milk contains proteins and nutrients that can help nourish water kefir grains in storage. The lactose provides food for the microbial community.

After rinsing clean grains, cover with fresh milk diluted 50/50 with water. Refrigerate for up to 2 weeks before replacing with fresh milk. The nutrients keep grains active longer.

Avoid Direct Contact with Metal

It’s best to avoid direct contact between water kefir grains and metal during the storage process. The minerals in the stainless steel can reportedly have adverse effects.

Use glass, plastic or ceramic containers. If using a metal lid, place a piece of parchment paper between the grains and metal. Preventing metal exposure keeps grains healthy.

Check for Molds and Yeasts

Periodically check on stored kefir grains for any visible molds, fungus or yeasts. Growth of white or black fuzz indicates contamination.

Discard any grains that have spoiled mold or yeast. Wash hands and sterilize equipment after handling to prevent spreading.

Healthy grains will have a uniform cauliflower shape with no powdery residue or discoloration.

Revive Stored Grains Slowly

After long-term storage, rehydrate grains slowly by gradually increasing feeding times. Start with 15-30 minutes in sugar water and slowly work back up to 24-48 hour ferments.

This gives the grains time to regain their strength and repopulate beneficial microbes after dormancy. Rushing the process risks killing off the grains.

Avoid Chlorinated Water

When rinsing and storing grains, always use filtered non-chlorinated water. The chemicals in tap water can damage the microbial community and compromise the grains’ health.

Let heavily chlorinated water sit out uncovered for 24 hours before using to allow the chlorine to evaporate out. Protect grains by keeping chlorine exposure to a minimum.

Store in Smaller Batches

Storing grains in smaller amounts can help extend their shelf life compared to one large batch. Split grains into a few smaller storage containers.

This limits exposure if some grains get contaminated. The smaller batches contain potential damage rather than losing your whole supply.


Properly stored water kefir grains can remain dormant for many months and regain activity with proper revival. Keeping grains cool, dry and out of contact with metals preserves the microbes.

Refrigerating in sugar water or milk provides short-term storage up to a month. Freezing dried grains with vacuum sealing can maintain viability for over a year.

Take care to limit contamination and chlorine exposure. With the right techniques, water kefir grains can be stored long-term and used again and again.

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