How to Make Kombucha: Complete Brewing Guide

A SCOBY (symbiotic culture of bacteria and yeast) is the pancake-like, somewhat rubbery culture responsible for converting sweetened tea into kombucha through fermentation; you can obtain one from a friend who brews, purchase one from a specialty supplier, or grow your own from a bottle of raw, unflavored store-bought kombucha.

To grow your own, pour a bottle of raw kombucha (labeled as containing live cultures) into a jar, cover with a breathable cloth, and wait 2-4 weeks in a warm spot for a new SCOBY to form on the surface.

A healthy SCOBY is typically pale tan to white, with a somewhat rubbery, pancake-like texture; brown stringy bits (yeast strands) hanging from it are completely normal and not a sign of any problem.

Always obtain a SCOBY along with some starter liquid, the already-fermented kombucha it comes packaged in, since this liquid provides the acidic environment new batches need to ferment safely and successfully.

Store extra or backup SCOBYs in a 'SCOBY hotel,' a jar of starter liquid kept at room temperature, which maintains healthy cultures in reserve for future batches or for sharing with other aspiring brewers.

Brew strong black or green tea using about 1 tablespoon of loose tea or one tea bag per 2 cups of water, steeping for 10-15 minutes to extract adequate strength for the fermentation process ahead.

Dissolve white sugar into the hot tea at a ratio of roughly 1 cup per gallon of finished liquid, stirring until fully dissolved; this sugar feeds the SCOBY during fermentation and is largely consumed by the process rather than remaining in the finished product.

Avoid using honey, artificial sweeteners, or flavored teas for the base fermentation, since these can introduce antimicrobial compounds or additives that interfere with the SCOBY's health and fermentation activity.

Let the sweetened tea cool completely to room temperature before adding the SCOBY, since hot liquid can damage or kill the delicate culture, undoing all the preparation up to this point.

Use filtered or dechlorinated water for brewing if your tap water is heavily chlorinated, since chlorine is specifically designed to kill microorganisms and can inhibit the SCOBY's fermentation activity.

Pour the cooled sweetened tea into a large glass jar, then add the SCOBY along with its accompanying starter liquid (typically about 1-2 cups per gallon batch), which jumpstarts fermentation with an already-acidic environment.

Cover the jar with a tightly woven cloth secured by a rubber band, which allows airflow (fermentation is aerobic) while keeping out fruit flies and other contaminants.

Place the jar in a warm spot, ideally 68-78°F, away from direct sunlight, and let it ferment undisturbed for 7-14 days, with warmer temperatures generally producing faster fermentation.

Taste-test starting around day 7 using a clean straw, checking for your preferred balance of sweetness and tartness; the kombucha becomes progressively more tart and less sweet as fermentation continues.

A new, pale SCOBY layer will typically form on the surface during this period, sometimes attached to the original and sometimes separate, both of which are completely normal signs of active, healthy fermentation.

Once first fermentation reaches your preferred taste, remove the SCOBY and set aside about 1-2 cups of the finished kombucha as starter liquid for your next batch.

Add fresh or frozen fruit, fruit juice, ginger, or herbs to clean glass bottles, typically about 1-2 tablespoons of flavoring per 16-ounce bottle, then fill with the fermented kombucha using a funnel, leaving an inch of headspace.

Seal bottles tightly with flip-top lids or tight-fitting caps, which traps the carbon dioxide produced during this second fermentation, building natural carbonation over the following days.

Let sealed bottles sit at room temperature for 2-5 days, 'burping' them briefly once daily by loosening the cap slightly to release excess pressure, which prevents bottles from over-pressurizing and potentially breaking.

Popular flavor combinations include ginger, mixed berries, apple-cinnamon, and citrus, though nearly any fruit or herb can be experimented with to discover your own preferred combinations.

Move bottles to the refrigerator once they've reached your desired carbonation level, which significantly slows further fermentation and preserves the flavor and fizz you've developed.

Refrigerated kombucha typically keeps well for 1-2 months, though flavor continues to slowly evolve over time even in cold storage, generally becoming slightly more tart the longer it sits.

Open bottles carefully over a sink, since well-carbonated kombucha can occasionally foam up dramatically when first opened, similar to a shaken soda bottle.

Strain out any fruit pieces or flavoring solids before drinking if desired, though many people simply drink around them or strain as they pour into a glass.

Start your next batch of first fermentation as soon as convenient using your reserved SCOBY and starter liquid, maintaining a continuous brewing cycle if you want a steady, ongoing supply.

A healthy SCOBY can be reused indefinitely, growing a new layer with each batch; you can either keep multiple layers together (a growing 'SCOBY stack') or peel layers apart to share with other brewers or start additional batches.

If you're not brewing continuously, maintain extra SCOBYs in a 'SCOBY hotel,' a jar with enough starter liquid to keep the culture submerged, checked periodically and fed with fresh sweet tea every few weeks to keep it healthy during storage.

Discard any SCOBY showing signs of mold, distinguished from normal yeast strands by fuzzy, colorful (often green, black, or pink) growth, since mold indicates contamination that shouldn't be used for continued brewing.

A thinning, unusually dark, or consistently sinking SCOBY can indicate declining health; starting fresh from a healthy backup or purchasing a new culture is often more practical than trying to nurse a struggling SCOBY back to full vigor.

Compost excess SCOBY layers you don't need, or explore alternative uses like SCOBY leather (a dehydrated, leather-like material) or animal treats, both popular ways to make use of a rapidly multiplying culture.

Use glass containers exclusively for brewing, avoiding metal (which can react with the acidic kombucha) and plastic (which can leach chemicals or harbor bacteria in scratches over repeated use).

Wash hands thoroughly before handling the SCOBY or any brewing equipment, and avoid using antibacterial soap directly on equipment that will contact the culture, since residue could harm the beneficial bacteria.

Keep brewing vessels away from other fermentation projects happening simultaneously in your kitchen, such as sourdough or other cultures, to avoid any risk of cross-contamination between different beneficial microorganism communities.

Clean all equipment between batches with hot water rather than harsh chemical cleaners, which can leave residue that potentially disrupts the delicate balance of organisms in your next batch.