Blackberry Mint Kombucha

Adding fruit and a small amount of sugar for the secondary fermentation results in a refreshingly fizzy kombucha.

Blackberry Kombucha

Serious Eats / Amanda Suarez

Why It Works

  • Straining the fruit-and-herb puree removes unwanted fiber and seeds, for a cleaner, smoother final beverage.
  • Adding fruit (plus a small amount of additional sugar) for the secondary fermentation provides plenty of food for the yeast to convert into CO2, for refreshingly fizzy results.

One of the great joys of brewing your own kombucha is its versatility: As long as you have a reliable, basic kombucha recipe, you can make virtually any flavor you want. This recipe builds on my basic jasmine tea kombucha,* with some fun changes during the secondary fermentation (what kombucha adepts refer to in shorthand as "F2") to create a refreshing blackberry-mint flavor. Jasmine tea works well as a mild, floral flavor base with relatively few bitter or tannic notes—a clean canvas for flavors and infusions.

* That recipe also offers a comprehensive review of the entire kombucha-making process, and is worth a read if you're new to kombucha brewing.

Adding fruit or herbal infusions is a common practice when bottling kombucha. While these ingredients primarily flavor the brew, the natural sugars in fruit provide extra fuel for yeast to produce even more carbon dioxide—the key to the fizzy quality we associate with kombucha. Fresh plant material, whether fruit, herbs, or even vegetables, also serves as an added source of wild yeasts, which can help accelerate fermentation. Fresh fruit can be added in chunks or as a puree or juice during bottling. 

In this recipe, I add a purée of blackberries and mint in the second fermentation—strong but complementary flavors that result in a refreshing, aromatic, and deeply crimson red kombucha. Puréeing the mixture increases the surface area of the infusion, resulting in a more intense flavor while requiring less fruit. I also add a small amount of sugar to the purée, which ensures there is plenty of sucrose available for the second fermentation.

One common problem when using fruit purées in kombucha is the amount of sediment and pulp they introduce to the beverage; even seeds can end up in the finished drink. While pulp and seeds don’t adversely affect the quality of fermentation, they can make the kombucha cloudy, fibrous, and otherwise “chunky” rather than clear and smooth. To mitigate the pulp in this recipe, I strain the puree through a few layers of cheesecloth before bottling.

Since there is so much added sugar and many potential sources of wild yeast, the second fermentation occurs quickly in this recipe—in as little as two days when fermenting at warmer temperatures (around 80℉). The resulting kombucha features large, frothy bubbles and boasts plenty of tart, faintly bitter blackberry flavor that plays beautifully with the cooling aroma of mint.   

Recipe Facts

Prep: 15 mins
Fermentation Time: 168 hrs
Total: 168 hrs 15 mins
Makes: 5 pints

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Ingredients

  • For the First Fermentation:
  • 12 cups (2880ml) filtered or distilled water, divided
  • 1 1/4 cups sugar (8 3/4 ounces; 248g)
  • 1/4 cup (24g) loose leaf jasmine tea
  • 2 cups (473ml) jasmine or green kombucha starter tea (see note)
  • 1 SCOBY (see note)
  • For the Second Fermentation:
  • 1 1/2 pounds (680g) fresh or defrosted frozen blackberries
  • 3 ounces (85g) fresh mint leaves
  • 2 tablespoons (25g) sugar

Directions

  1. For the First Fermentation: In a large 4-quart or larger pot, combine 4 cups (960ml) water with the sugar and bring to a boil over high heat, stirring occasionally to help fully dissolve sugar. Off heat, stir in tea leaves and let steep until tea registers roughly 150°F (65°C) on an instant-read thermometer, about 15 minutes. Stir in remaining 8 cups (1920ml) water and let cool until tea registers 85 to 90°F (30 to 32°C).

    Two image collage of sugar being dissolved in a pan and then tea being brewed

    Serious Eats / Tim Chin

  2. Set a fine-mesh strainer over a one-gallon glass jar that has been run through a dishwasher cycle or sanitized with a product like Star San. Strain tea through it; discard tea leaves. Stir in kombucha starter until well distributed. Gently place SCOBY on top (you should have at least 2 inches of headspace in the jar after adding the SCOBY). The SCOBY may float or sink to bottom of jar; either is normal.

    Three image collage of straining into jar, pouring kombucha mixture into jar, and jar with scoby floating in it.

    Serious Eats / Tim Chin

  3. Cover jar with a double layer of coffee filters and secure with a rubber band. Store in a dark area between 70 and 80°F (21 to 27°C) and let ferment until kombucha tastes sour and small bubbles rise to surface, and a new layer of SCOBY has formed at surface, about 7 days and up to 4 weeks (pH should register roughly 2.9 on a pH meter or pH strips).

    Two image collage of top of Kombucha at the start and after 8 days of fermentation

    Serious Eats / Tim Chin

  4. For the Secondary Fermentation: Set a fine mesh strainer over a medium bowl. Line strainer with 3 layers of cheesecloth, leaving 6 inches overhang on all sides. In a food processor, process blackberries, mint, and sugar, pausing once halfway through to scrape down sides, until mixture is pureed, about 1 minute. Scrape blackberry puree into strainer and allow juice to drain through into bowl. Gather overhanging cheesecloth, twist to close, then squeeze puree to release as much juice as possible; you should have about 1 1/2 cups (355ml) juice once done.

    Four Image collage of creating blackberry puree for kombucha flavoring

    Serious Eats / Tim Chin

  5. Thoroughly wash and dry five 16-ounce (1-pint) twist-cap or flip-top glass bottles. Using clean hands, remove SCOBY from kombucha and place on plate. Then, using a funnel, fill each bottle with 1/4 cup (60ml) blackberry juice. Stir kombucha with a wooden spoon, making sure sediment is evenly dispersed, then fill each bottle with kombucha, making sure to leave 1 to 1 1/2 inches of headspace in each bottle (you should have about 2 cups of extra kombucha that won't fit in the 5 bottles; this kombucha can be used as starter for your next batch). Seal bottles and store in a dark area between 70 and 80°F (21-27°C) until beverage reaches desired level of carbonation, 3 days to 2 weeks. Check one bottle periodically to monitor carbonation: it is ready when you see small bubbles rising fairly rapidly to the top, even when capped; if using twist caps, the cap will pop up slightly when a good level of carbonation is reaches; if using flip-top bottles, you may need to open one bottle to check the carbonation, resealing if there isn't enough fizz. When kombucha has reached desired level of carbonation, move bottles to refrigerator and store for up to 8 weeks.

    Side by side images of blackberry kombucha being bottled

    Serious Eats / Tim Chin

  6. To Continue Brewing Future Batches of Kombucha: Repeat Steps 1 to 5 using the leftover kombucha as starter along with reserved SCOBY and new batches of the blackberry-mint puree.

Special Equipment

Large fine-mesh strainer, one-gallon glass jar, funnel, large coffee filters, five 16-ounce (1-pint) twist-cap bottles or flip-top bottles; dishwasher or a sanitizer like Star San (for cleaning vessels); pH meter or pH strips

Notes

Starter tea can either be from a prior batch (preferred) or from a bottle of store-bought kombucha. Use an unflavored jasmine or green tea kombucha if possible. For best results, use jasmine or green tea kombucha from a previous batch. 

The best source of a SCOBY is a friend or acquaintance who regularly brews kombucha. You can also buy them commercially, but note that SCOBY's that are sold dry or unsubmerged in starter liquid tend to perform weakly in comparison to those sold fresh and packaged in starter tea

Make Ahead and Storage

The finished bottled kombucha can be refrigerated for up to 8 weeks.