Kombucha tracker for iPhone

Better kombucha, batch after batch.

Fermenta tracks every batch from sweet tea to the fridge. It tells you when to taste, bottle, and chill, and remembers what worked last time.

App Store App Store

Coming soon

For iPhone with iOS 26 or later

  • No account needed
  • Works offline
  • No subscription

40 built-in flavors, plus your own

  • Ginger
  • Lemon
  • Hibiscus
  • Peach
  • Blueberry
  • Mint
  • Mango
  • Lavender
  • Strawberry
  • Elderflower
  • Passion Fruit
  • Turmeric

How it works

Kombucha is simpler than it looks.

Fermenta will guide you through the process and help you know what to pay attention to along the way.

  1. 01

    Brew

    Sweet tea, a SCOBY, and starter liquid in a clean glass jar.

  2. 02

    First fermentation

    The culture turns the sugar into acidity over 7 to 10 days.

  3. 03

    Taste

    Taste it to check the balance between sweet and tart.

  4. 04

    Second fermentation

    Bottle it, add flavors, and let the carbonation build.

  5. 05

    Chill

    The fridge slows fermentation and lets the carbonation settle.

  6. 06

    Enjoy

    Pour a glass, rate the batch, and plan the next one.

01 Every batch

Always know what’s next

Every batch shows its day, its target, and the one thing to do next: bottle it, chill it, or just wait. Extend a stage that needs more time, or skip ahead when it’s ready early.

Fermenta never moves a batch forward on its own. You always decide when it’s ready.

Jasmine Green's batch detail screen: day 5 of 7, 57% of the way, ready to bottle in 3 days, with Bottle and start F2 as the next step. Jasmine Green's batch detail screen: day 5 of 7, 57% of the way, ready to bottle in 3 days, with Bottle and start F2 as the next step.

02 Reminders

Never miss a bottling day.

Get a nudge when a batch needs you: time to taste, ready to bottle, check the carbonation, ready for the fridge. Act right from the notification, without opening the app.

Choose which reminders you get, and when they arrive, in Settings.

A Fermenta reminder on the Lock Screen: Ready to bottle. The brew Jasmine Green has reached the end of F1. A Fermenta reminder on the Lock Screen: Ready to bottle. The brew Jasmine Green has reached the end of F1.

03 Widgets and calendar

Your brews, one glance away

Small and medium widgets follow one brew, with an action button built in. The large widget shows up to three batches at once. The calendar puts bottling, chilling, and ready dates side by side.

Touch and hold the app icon to jump straight into a batch or start a new one.

A medium Fermenta widget on the Home Screen: Ginger Peach, day 2 of 4, ready to chill in 3 days. A medium Fermenta widget on the Home Screen: Ginger Peach, day 2 of 4, ready to chill in 3 days.
The Fermenta calendar for September, with dots on the days a batch needs attention. The Fermenta calendar for September, with dots on the days a batch needs attention.

04 Logs and flavors

Track how the brew changes

Log flavor, pH, temperature, and carbonation as the batch develops. When you bottle, split it into groups and give each one its own flavors, from 40 built-in options or your own.

The new log sheet with flavor set to tart, a temperature of 26 °C, and a date. The new log sheet with flavor set to tart, a temperature of 26 °C, and a date.
The flavor picker with ginger and peach selected. The flavor picker with ginger and peach selected.

05 Every finished batch

Learn from every batch

Rate a finished batch, add a tasting note, and brew it again with one tap: same tea, same amounts, same durations. Share it as a summary card, with or without dates.

Hibiscus Lemon, completed in 10 days and rated 4 out of 5, with Brew this again as the next step. Hibiscus Lemon, completed in 10 days and rated 4 out of 5, with Brew this again as the next step.
The share card for Hibiscus Lemon kombucha, with its rating, flavors, and brew timeline. The share card for Hibiscus Lemon kombucha, with its rating, flavors, and brew timeline.

Tools

A brewing companion, not just a timer

Plan a batch, troubleshoot one, or look up a term, all inside the app.

Ratio calculator

Tea, sugar, and starter liquid for any volume.

Brew guide

First and second fermentation, step by step, with a closer look at each one.

Troubleshooting

Mold, low carbonation, or off smells: what to do.

FAQs

Quick answers to common questions.

Glossary

SCOBY, pellicle, starter liquid: the brewing terms, from A to Z.

Fermenta Pro

A home for your spare cultures

A SCOBY hotel is a vessel where spare cultures rest in starter liquid between batches.

Log each feeding, get a reminder to check on it every one to six months, and start your next batch straight from the hotel.

Main hotel, the default SCOBY hotel: black tea, a 4 liter vessel, and a care reminder every 2 months. Main hotel, the default SCOBY hotel: black tea, a 4 liter vessel, and a care reminder every 2 months.

Pricing

Free to start. Yours for good if you upgrade.

Fermenta Pro is a single one-time purchase. No subscription.

Fermenta

Free

  • One batch fermenting at a time
  • Reminders, widgets, and calendar
  • Logs, ratings, and sharing
  • Calculator, guide, mold check, and more

Brew as many batches as you like, one at a time.

Fermenta Pro

One-time purchase

  • Everything in Free
  • Unlimited batches at the same time
  • SCOBY hotel
  • Pay once, keep it for good

The price is shown in the App Store before you buy.

Privacy

Your data stays on your phone

Read the privacy policy
  • No account

    Open the app and start brewing.

  • Stored on your iPhone

    Your brews live on your device.

  • Optional iCloud sync

    Through your own iCloud account.

  • Works offline

    No connection needed to log a batch.

  • No ads

    And your data is never sold.

  • No tracking

    Nothing follows you across other apps.

FAQ

Questions and answers

Is Fermenta free?

Yes. Fermenta is free with one batch fermenting at a time. Fermenta Pro is a one-time purchase that unlocks unlimited batches at the same time and the SCOBY hotel.

Can I add a batch that is already underway?

Yes. For a batch still in F1, select its original start date. For a batch already in F2, choose Already brewing and enter its F1 and F2 dates, bottling details, and flavors.

Is there a subscription?

No. Fermenta Pro is a single purchase. You pay once and keep it.

Does Fermenta move brews to the next stage automatically?

No. Dates, progress, and reminders help you decide when a brew needs attention, but you choose when to bottle it, start chilling, or finish it. You can also move it forward early or extend the current stage.

Does it work on iPad or Android?

Fermenta is made for iPhone. There is no iPad or Android version.

Does changing units alter my saved recipes?

No. Switching between metric and imperial only converts how quantities and temperatures are displayed. The physical amounts saved for your brews remain the same.

Can I use Fermenta without an internet connection?

Yes. Your data is stored locally and the app continues to work offline. If iCloud is available, changes sync with your other devices when a connection returns.

How do I share a brew?

Completed brews can be shared as a generated summary image. Open the completed brew, tap Share, choose whether to include dates, and use the iPhone share menu.

Which languages does it support?

English, Spanish, Portuguese, German, French, and Italian.

Does Fermenta tell me if a batch is safe to drink?

Fermenta is a tracking tool, not a food safety or medical guide. Follow safe fermentation practices and decide whether a batch is safe to consume.

Nothing fermenting yet?

Start your first batch and Fermenta will keep count of the days.

App Store

Coming soon

For iPhone with iOS 26 or later