Water Kefir has the delicious appeal of a fruity, sweet-tart soda. A probiotic powerhouse, kefir offers a richer, more diverse population of beneficial microbes than either yogurt or kombucha. And its short fermentation cycle makes it one of the easiest and quickest fermented foods to make.
Completely caffeine-free, water kefir makes a wonderfully healthy alternative to soda. The culture consumes sugar and produces a little fructose, which tastes sweeter than other sugars. So water kefir tastes somewhat sweet, but only contains a small amount of sugar (fructose). It is also perfect as a thirst-quenching energy drink or a healthy probiotic base for smoothies.
Natural Carbonation and the Benefits of Temperature Control
Water kefir needs to be kept above 70 °F / 21 °C to reduce the risk of contamination and keep the culture balanced and healthy. Home brewers in cooler environments often experience difficulty achieving the natural fizz of water kefir. We recommend maintaining a temperature of 75 °F / 24 °C to keep the culture balanced and active enough to produce water kefir’s appealing natural carbonation.
Temperature control will also allow the water kefir to develop consistently from batch to batch, making it easy to get predictable, optimal results. Setting your Proofer to 70-75 °F / 21-24 °C will produce a mild brew, or warmer temps can be chosen to encourage a riper flavor and stronger carbonation, up to 82 °F / 28 °C.
Water Kefir Grains
The key to making water kefir is obtaining water kefir “grains,” the little cellulose nuggets that contain the culture. They can be ordered online, or if you have a friend who brews this delicious drink you can ask for a tablespoon or two of their grains. When cultured in healthy conditions, the grains multiply, so there’s often plenty to share.
Because the culture is related to classic kefir (which is grown in calcium-rich milk), it loves a mineral-rich environment. Using a less refined sugar, such as organic blond sugar or turbinado, can help feed your culture the nutrients it loves, especially if your water is low in minerals.
If you are starting with dehydrated grains, it can sometimes take a fermentation cycle or two after the initial hydration period to get the culture up and running.
Printable Instructions instructions imprimable
Yield: two quarts / liters. The recipe can easily be halved or multiplied. The Folding Proofer will hold up to eight 1-quart/ 1-liter size jars.
||1 C / 250 ml
||250 g / 9 oz
||100 g / 3.5 oz
|Fresh water kefir grains**
||11 g/ 0.4 oz
|Additional water, non-chlorinated
||6½ C / 1.6 L
||1.6 L / 56 oz
*Preferably a less-refined type such as organic blonde sugar Do not use honey.
**If the water kefir grains are dried, they need to be properly hydrated and activated before the first use.
Equipment: Brod & Taylor Folding Proofer, a stainless steel or plastic funnel (no aluminum), a fine stainless steel or plastic strainer and heat proof mason jar(s), not more than 8” / 20cm tall. An instant read thermometer is helpful for making sure the water mixture has cooled adequately.
Get Ready. Set up the Proofer with the rack in place and the thermostat at 75 °F / 24 °C. Glass mason jars and a thermometer (if used) should be thoroughly clean and dry. Set out coffee filters or clean cloths and rubber bands to cover jars.
Make the Water Mixture. Combine all of the sugar with 1 C / 250 ml of water and heat, stirring, until the sugar dissolves (about 150 °F / 65 °C). Remove from heat and cool for ten minutes.
Transfer the warm sugar water to mason jars, dividing evenly between jars if using more than one. Add additional non-chlorinated water to the jars to fill, leaving a small space at the top to prevent spills.
Check the Temperature. Before adding the culture, make sure the sugar-water mixture is below 85 °F / 29 °C. If necessary, allow the mixture to cool.
Add the Water Kefir Grains and Cover. Add the grains to the sugar water, using about 2 T / 5.5 g of grains for each quart / liter. Cover the jars with a breathable cover such as a coffee filter or clean cloth, secured with a rubber band. The culture does not require oxygen, but a breathable cover prevents leaks and explosions in the Proofer and also helps minimize trace alcohol levels produced by the culture.
Ferment for 48 Hours. Place jar(s) in the Proofer to ferment. For the most accurate temperature control, arrange the jars so that they are not directly over the center of the Proofer. Allow the culture to ferment for two days / 48 hrs at 75 °F / 24 °C. For a riper flavor or stronger carbonation, the temperature can be increased to 78 °F / 26 °C, or up to 82 °F / 28 °C.
When the water kefir is done, the surface will have a few visible bubbles, it will smell a bit yeasty (like bread dough), and should taste mild and slightly sweet. Even though the acidity will have increased with the pH at about 4.3-4.5 at this point, the water kefir will not yet taste very tart.
Non-Carbonated Water Kefir for Smoothies
The easiest way to finish your Water Kefir is to store it plain and use it for smoothies. No flavoring is needed, as water kefir has a slightly sweet, neutral taste that will blend easily with many different smoothie recipes. Plain water kefir can also be blended with fresh or frozen fruit and frozen in popsicle molds.
When the 2-day fermentation is complete, fit a clean storage jar with a non-aluminum funnel and fine strainer, then pour the fermented water kefir through, allowing the grains to collect in the strainer. Seal jars with loosely screwed on lids and refrigerate. Use the grains to start your next batch, or store them according to the directions here.
Create Naturally Carbonated Water Kefir
Water kefir turns into a delightful sweet-tart probiotic soda through a second fermentation in the bottle. We recommend using swing-top bottles because they are strong enough to prevent explosions and tightly sealed enough to capture carbonation.
If you’re just getting started with water kefir, consider flavoring your bottles with one of the following beginner-friendly options:
- Sweet Fruit Juice: fill each bottle about one-fourth full with juice. Grape, cherry, apple, or orange juice are all great options. The juice will be less sweet and a little more tart after fermenting in the bottle.
- Citrus Water Kefir: add about 1 T / 15 ml lemon or lime juice per 8oz / 250ml, or fill bottles about one-fourth full with grapefruit juice. If desired, add about ½ tsp / 2 g sugar per 8oz / 250ml to offset the tart juice and encourage carbonation.
- Ginger: add plenty of thin-sliced or minced fresh ginger to each bottle. Use a little more than you think you need and consider storing a day or two in the refrigerator after the bottle fermentation is complete, as the ginger will be somewhat slow to impart its flavor.
After adding flavoring to your bottles, fit one with a non-aluminum funnel and strainer. Before pouring in the fermented water kefir, give it a good stir with a spoon to evenly distribute the probiotics. Then pour it into the bottles, allowing the grains to collect in the strainer. Leave a little airspace at the top of the bottle. Use the grains to start your next batch, or store them according to the directions here.
Second Fermentation in the Bottle
Seal the bottles and allow them to ferment at cool room temperature for 2-3 days below 70 °F / 21 °C. Check the carbonation of one of the bottles after two days by tasting a little. If it’s noticeably fizzy, chill the bottles. If it isn’t yet fizzy enough, allow the bottles to ferment 12-24 hours more. When a cool environment is not available, bottle ferment for a shorter time of 1-2 days and consider burping the bottles to prevent explosions. After bottle fermentation is complete, chill and serve cold.