Items you will need
- Water kefir
- Non-metallic fine mesh strainer
- Sturdy plastic bag, or sterile jar with lid
- Boiled or distilled water, room temperature
- Clean towels
- Wire cooling rack
- Zipper-seal storage bag, or sterile jar with lid
Kefir is a fermented probiotic beverage native to Central Asia, much like kumiss and yogurt. It is made with lumpy colonies of starter, referred to as kefir "grains." Traditionally kefir is made from milk, but starters can adapt to any liquid containing modest amounts of sugars. The kefir grains reproduce, once adapted, providing the kefir for future recipes. Prudent kefir makers dehydrate spare grains to serve as a backup in case their culture should become contaminated.
Separate the grains from your water kefir, using a non-metallic fine-mesh strainer. Divide the grains, setting aside the portion you wish to dry in a plastic bag. Return the rest to their usual jar.
Pour distilled water or boiled, cooled water over the kefir grains in the bag or in a sterile jar. Swirl the bag or jar to rinse the grains and drain them once again in the non-metallic strainer. Repeat the rinsing process.
Empty the grains onto a clean, smooth kitchen towel. Let them drain for 30 minutes, then transfer them to a new towel sitting on a wire cooling rack. Cover them with another towel.
Dry the grains for 1 to 2 days until they are hard and brittle. Store them in an airtight zipper-seal bag or other similar container. For best results, use the dried grains within six months, or replace them with another batch.
To minimize the risk of contamination, iron your kitchen towels with a steam iron immediately before using them. The high temperature and steam from the iron kills any microorganisms on the surface of the towel. Use kitchen towels with a flat weave, not terry cloth.
Apply the same technique to dehydrate grains for regular milk kefir, but it takes 2 to 4 days rather than 1 to 2.