How to Activate Milk Kefir Grains


Our Kefir Grains are sold in a dehydrated state, which preserves the yeast and bacteria in the culture while greatly allowing the culture to be shelf-stable and therefore far safer to ship or sell in a retail location. Our Kefir Grains can be activated for use through the following rehydration process. This process generally takes 3-7 days.





Prepare the Rehydration Solution

Equipment. Click here for more information on choosing the best brewing container, cover system, utensils, and more.

  • One pint or quart size glass jar
  • A plastic or wood stirring utensil (we do not recommend using metal but if metal must be used, ensure that it is stainless steel)
  • A breathable cover for the car such as a tight-weave towel, paper towel, or paper coffee filter
  • A rubber band to secure the cover to the jar
  • Optional: A fine mesh strainer (plastic or stainless steel) for removing the kefir grains from the finished kefir

Ingredients. Click here for more information on choosing the best milk source for making Kefir.

  • One packet dehydrated Milk Kefir Grains
  • Fresh Cow or Goat Milk. Do not use coconut, soy, nut milk, or any alternative varieties of milk. If using pasteurized milk, do not use milk that is close to the “use by” date. If using raw milk, we do not recommend using milk that is more than a few days old due to rising bacteria counts which can conflict with bacteria and yeast present in the Kefir Grains.

A note about hygiene. When working with Kefir Grains, it is important not to introduce competing bacteria to the process. Be sure to wash and rinse your hands well prior to working with the milk or the Kefir Grains. Also be sure to thoroughly clean and rinse the container and all utensils that will come in contact with the Kefir Grains. Beware soap and food residue the dishwasher may have missed. When in doubt, give everything an extra rinse. The brewing vessel can be cleaned with regular soap and hot water (rinse several times very well) or with vinegar. Never use bleach on any item that will come in contact with the Kefir Grains.

Activating the Kefir Grains

  • Place the dehydrated kefir grain in one cup of fresh milk and leave in a partially sealed container for 24-hours at room temperature.  
  • Each day, strain the grain from the milk and add the kefir grains to fresh milk.  This process should occur even if the milk does not coagulate (kefir).  The strained milk can be discarded or used for cooking provided it looks and smells okay.

Choose a safe spot. An ideal culturing spot should be relatively warm but not excessively so. Temperatures between 70° and 80° are ideal. An ideal spot for making Kefir should be out of direct sunlight. Indirect light or darkness is neither favorable nor problematic. Be sure the spot has reasonably good airflow as access to oxygen benefits the fermentation process. In addition, be sure the Kefir is not fermenting near a garbage or compost bin, bread made with commercial yeast, or any other cultured foods such as kefir, yogurt, sourdough, sauerkraut, etc. Cross-contamination by stray yeasts and bacteria can be problematic for the Kefir Grains.


 Signs the Rehydration Process is Complete

  • Within 4-7 days, the 24-hour milk batch will begin to smell sour but clean.  Eventually the milk will start to coagulate (kefir) within 24-hours (please note, if the area where your kefir grains are kept is cooler than 70 degrees, it may take 30-48 hours to see coagulation).
  • The first few days may yield an overgrowth of yeast or a layer or froth or foam on the surface of the milk.  Within 5-7 days, the bacterial balance should stabilize and the kefir will begin to smell clean, sour and possibly of fresh yeast.  Under some circumstances, the kefir grains may take 2-4 weeks to start to making kefir.  Please be patient during this process.
  • Once the milk is reliably turning to pleasant tasting and pleasant smelling kefir within 24-48 hours, your kefir grains are ready to generate regular batches of kefir.

Signs of Problems During Rehydration

While problems during rehydration are relatively uncommon, it is important to keep an eye out for these few signs that the process isn’t proceeding normally.

Time frame. If the milk is changed every 24 hours for more than 10 days and the milk is not turning to kefir within 24 hours, allow the milk and kefir grains to sit for an additional 24 hours (48 hours total). Ambient temperature in particular can affect how quickly the kefir forms. If the milk still fails to coagulate contact Customer Service for additional information to determine if the culture is inactive and if a replacement is needed.

Mold. While unusual, mold can and does occasionally develop and can generally be seen by the formation of white, green, orange, red, or black spots on the surface of the milk. If mold does develop, immediately toss the entire batch including the Kefir Grains. Do not try to salvage a moldy batch or a moldy Kefir Grains (even if there isn’t any mold directly on the Kefir Grains themselves). Doing so is dangerous to your health. Contact Customer Service for additional assistance.

Pests. Culturing Kefir is very attractive to ants and fruit flies which is why we recommend using a tight-weave cover and securing the cover with a tight rubber band to keep the invaders out. If you find worms (maggots) have infested your batch, this is a sign that fruit flies or house flies have invaded and laid their eggs. If this happens, immediately toss the entire batch including the Kefir Grains. Do not try to salvage an infested batch or an infested Kefir Grains. Doing so is dangerous to your health. Contact Customer Service for further assistance.

Next Steps

Once your Kefir Grains have finished rehydrating it is time to use it to make your first official batch of Kefir.  Click here to view our comprehensive instructions and how-to video for making Dairy Kefir.







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Related Products:

Milk Kefir Grains Milk Kefir Grains

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