Water Kefir from 'Mastering Fermentation'

Blueberry Water Kefir, Coconut Water Kefir, Hibiscus-Ginger Water Kefir
Photograph: Ed Anderson

Milk kefir is a pretty common sight in the dairy aisle these days—or at least it is in California. Much more mysterious is its lactose-free cousin, water kefir. Both drinks are fermented with similar SCOBYs (symbiotic colonies of bacteria and yeast), but milk kefir grains feed on the natural sugars in the milk while water kefir needs additional sugar or fruit juice to get going. Mary Karlin provides recipes for both in her new cookbook, Mastering Fermentation. Today, we're trying our hand at the water-based version.

Why I picked this recipe: I was super curious what water kefir would actually taste like. Would it be sour like kombucha? Yeasty like good beer? Flat and weird? I had to try it.

What worked: Despite working with unfamiliar ingredients, this was a super easy project. The plain water kefir was slightly sweet and slightly yeasty, but ultimately pretty boring. Once I jazzed it up with a few pieces of ginger, however, I loved it. The ginger transformed the beverage into a barely sweet soda and a perfect thirst quencher.

What didn't: You don't need to use fancy glass bottles to store the finished kefir if you don't have them. Clean mason jars work just as well.

Suggested tweaks: You will need to source water kefir grains for this recipe. I ordered mine online from Cultures for Health and they worked great. I have also heard of friends having success finding kefir grains on Craigslist, but it's hard to verify how well they've been taken care of. You can flavor your water kefir in one of two ways. First, you could put the hydrated grains into fresh fruit juice or coconut water instead of plain water. Or you can add small pieces of fruit, vegetables, or tea leaves (like blueberries, ginger, or hibiscus) to the kefir once you've strained out the grains. The additional sugars from these additions will make the kefir lightly carbonated. If you want to use the kefir as a starter culture, leave it plain.

Reprinted with permission from Mastering Fermentation: Recipes for Making and Cooking with Fermented Foods by Mary Karlin. Copyright 2013. Published by Ten Speed Press, an imprint of the Crown Publishing Group, a division of Random House. All rights reserved. Available wherever books are sold.

Recipe Facts

Active: 30 mins
Total: 0 mins
Serves: 8 servings
Makes: 2 quarts

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  • 12 cups non-chlorinated water, at room temperature (see note)

  • 3/4 cup raw unrefined cane sugar or Sucanat

  • 2 teaspoons dehydrated water kefir grains


  1. To hydrate the grains: The first time you use the dehydrated grains (or if they have been stored for an extended period of time), they need to be hydrated to become active. In a small pan, heat 2 cups of the water over medium-high heat to just boiling. Place 1/4 cup of the raw sugar in a 1-quart glass jar and cover with the hot water. Stir to thoroughly dissolve the sugar. Add enough room-temperature water to bring the level of the liquid to the shoulder of the jar. Cool the mixture to room temperature and then add the grains. Cover the opening with fine-weave cheesecloth or a kitchen towel and secure with a rubber band. Allow the mixture to sit at room temperature for 3 to 4 days until the grains are plump. You are taking a risk if you let them sit any longer than 5 days, as the grains may start to lose their potency from lack of food (sugar).

  2. To make the kefir: In a small pan, heat 2 more cups of the water over medium-high heat to just boiling. Divide the remaining 1/2 cup sugar between two 1-quart glass jars and cover evenly with the hot water. Stir to thoroughly dissolve the sugar. Add enough room-temperature water to bring the level of the liquid to the shoulder of the jar.

  3. Cool the mixture to room temperature, and then add equal amounts of the loose plump grains in each jar. Cover the jar opening with fine-weave cheesecloth or a kitchen towel and secure with a rubber band.

  4. Allow the mixture to sit at room temperature for 24 to 48 hours, depending on the level of sweetness you want. Shorter time will result in a sweeter kefir; longer will be less so. Do not exceed 72 hours.

  5. About 12 hours before you are ready to strain the kefir, start a new batch of sugar water to prepare for the next batch of kefir. This sugar water will need to be ready to receive the grains once you have strained the kefir.

  6. Once it has reached the desired level of sweetness, use a dedicated fine-mesh nylon strainer to strain off the liquid into a spouted glass measuring vessel. Using a funnel, fill two 1-liter swing-top bottles. Place the captured grains in the new batch of sugar water to store.

  7. Secure the caps on the bottles and leave at room temperature until ready to consume. In a day or so, tiny bubbles of carbonation will appear. This will increase as time passes and if you add fruit to the kefir. Water kefir does not need to be refrigerated unless you want it chilled. It’s best to consume within 10 days after opening a bottle.

  8. Unused grains can be fed and stored, covered, in sugar water (1/4 cup sugar to 1 quart water), and refrigerated for up to 2 weeks. Bring the mixture to room temperature before using the grains for a new batch of kefir. For longer periods of storage, the grains should be laid out to dehydrate, stored in an airtight container, and refrigerated. This process returns the grains to their original state.

  9. Note: Kefir grains require minerals to thrive. Hard, mineral-rich water such as well water or spring water is best. Do not use filtered water because too many of the minerals will have been removed. If using tap water, first bring it to a boil to remove any possible chlorine, and then cool it to room temperature before using. Supplementing with Trace Mineral Drops (1/8 teaspoon per quart of water) is a good security measure. These can be purchased from the same source as your grains.

Nutrition Facts (per serving)
73 Calories
0g Fat
19g Carbs
0g Protein
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Nutrition Facts
Servings: 8
Amount per serving
Calories 73
% Daily Value*
Total Fat 0g 0%
Saturated Fat 0g 0%
Cholesterol 0mg 0%
Sodium 14mg 1%
Total Carbohydrate 19g 7%
Dietary Fiber 0g 0%
Total Sugars 19g
Protein 0g
Vitamin C 0mg 0%
Calcium 11mg 1%
Iron 0mg 0%
Potassium 1mg 0%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)