Overview
FermentAdvisor is a ferment-tracking app. We help home fermenters plan a ferment, check in on it while it's active, and log the result — kombucha, kimchi, sauerkraut, pickles, hot sauce, yogurt, kefir, vinegar, miso, tepache, tejuino, and the perpetual cultures (sourdough starter, SCOBY, kefir grains, vinegar mother) that feed several of them. This policy explains what data we collect when you use the app, how we use it, and the rights you have over it.
FermentAdvisor requires an account from first launch — there is no anonymous mode. You get 8 free lifetime uses (starting a jar, running a check, or logging a finish each draw from that pool) before Pro or a rewarded ad is needed; checks that identify a safety issue — distinguishing healthy culture from mold, for example — are always free, on every tier.
We collect the minimum data needed to make the app work. We do not sell your data to advertisers or data brokers. We do not track you across other apps and websites.
Data We Collect
Account data
Signing in requires your email address, which we use to send a one-time, 8-character sign-in code. There is no password to create and no separate account-creation step — entering a valid code both signs you in and creates your account if you're new.
We assign each account an internal user ID (a randomly-generated identifier) that links you to your ferment jars, check-in history, and subscription state.
We do not collect your name, phone number, address, date of birth, or other personal identifiers unless you choose to enter them as part of your ferment notes.
Usage data
While you use the app we collect basic usage events — ferments you plan, check-ins and logs you submit, and which app screens you interact with. This helps us understand which features are useful and where the app falls short.
We also collect crash reports and basic device diagnostics (device model, OS version, app version) to fix bugs and improve reliability.
Photos and check-ins
When a check-in benefits from a photo — most importantly telling a healthy ferment (or harmless kahm yeast) apart from something to discard — we send that photo to our AI processing partner (Anthropic) to generate the read you see in the app. When you log a finished ferment, we store the photos and notes you submitted so you can review them later in your library.
We do not use your photos to train AI models, share them with other users, or use them in marketing without your explicit permission.
Subscription data
If you subscribe to Pro, we store your subscription tier (free or pro) and entitlement expiry. The underlying payment is handled by Apple or Google — we never see your credit card or financial information.
How We Use Your Data
We use the data we collect to:
- Provide the FermentAdvisor service — generate ferment schedules, check-in reads, and finished-batch diagnoses based on the ferments and photos you submit.
- Save and recall your jars, check-in history, and finished-batch library when you sign in.
- Send you authentication emails (sign-in codes) and respond to your support requests.
- Send local reminders for the next thing a jar needs (a check-in, a feed, a bottle date) — these are scheduled on your own device and are not sent through our servers.
- Enforce usage limits fairly — free accounts get 8 lifetime uses across starting jars, checks, and logs, then a rewarded ad or Pro; safety-classed checks never count against this.
- Show a rewarded video ad in the free tier when you choose to watch one to unlock another use.
- Diagnose crashes and improve the app's reliability and quality.
We do not use your data to make decisions about you outside the app, to build advertising profiles, or to sell to data brokers.
Third-Party Services
Anthropic (AI processing)
We use Anthropic's Claude API to generate the AI-powered parts of the app — Plan a Ferment (schedule and guidance), Check In (a read on your ferment, including any photo you submit), and Log a Ferment (the finished diagnosis). When you use these features, your ferment details and any photos you submit are sent to Anthropic for processing.
Anthropic processes this data on our behalf under their API data policy and does not use it to train their AI models. See Anthropic's Privacy Policy.
RevenueCat (subscriptions)
If you subscribe to Pro, RevenueCat manages your subscription state across the App Store and Google Play on our behalf. They receive your internal FermentAdvisor user ID and your subscription information (start date, expiry, renewal status). They do not receive your email, photos, or ferment details. See RevenueCat's Privacy Policy.
Cloudflare (infrastructure)
FermentAdvisor's backend runs on Cloudflare's infrastructure — Workers (serverless functions), D1 (database), and KV (cache). Cloudflare stores the data we collect on our behalf in encrypted form. See Cloudflare's Privacy Policy.
Resend (email)
We use Resend to deliver authentication emails (sign-in codes). Resend receives your email address and the code content only for delivery. They do not use this for their own marketing. See Resend's Privacy Policy.
Google AdMob (advertising)
In the free tier, we show a short rewarded video ad when you exceed the free-use cap and choose to watch one to unlock another use. Google AdMob serves this ad and may use your device's advertising identifier to personalize it, subject to your device's privacy settings.
On iOS, you can control whether AdMob receives the identifier via the App Tracking Transparency prompt; on Android, you can opt out of personalized ads or reset your advertising ID in your device's privacy settings. See Google's Privacy Policy and Ads Help.
Data Retention
We retain account data for as long as your account is active. If you stop using the app, we retain your account data for up to 24 months from your last sign-in, then we anonymize or delete it on a rolling basis.
Crash reports and aggregated usage events are retained for up to 90 days, then deleted.
Photos and finished-batch logs are retained as part of your saved library until you delete them individually or close your account.
Your Rights
Access and portability
You can request a copy of the personal data we hold about you. Send your request to privacy@fermentadvisor.app from the email address tied to your FermentAdvisor account. We respond within 30 days.
Account and data deletion
You can request deletion of your FermentAdvisor account and all associated data at any time.
To request account deletion:
- Send an email to privacy@fermentadvisor.app from the email address tied to your FermentAdvisor account.
- Use the subject line "Account deletion request."
- We confirm receipt within 3 business days and complete deletion within 30 days.
What gets deleted: your account record (email address, internal user ID), all saved jars and their check-in history, all finished-batch logs and any photos you uploaded, your subscription state, your usage counters, and all active session tokens.
What we retain after deletion: aggregated, anonymous usage statistics with no personal identifiers; billing records required by tax law (handled by Apple or Google, not by us directly) for up to 7 years.
California residents (CCPA)
If you reside in California, you have additional rights under the California Consumer Privacy Act, including the right to know what categories of personal information we collect, the right to delete your personal information, the right to correct inaccurate personal information, and the right to opt out of any sale or sharing of personal information.
FermentAdvisor does not sell your personal information and does not share it for cross-context behavioral advertising. To exercise CCPA rights, contact privacy@fermentadvisor.app.
EEA/UK residents (GDPR)
If you reside in the European Economic Area, the United Kingdom, or Switzerland, you have rights under the GDPR including access, rectification, erasure, restriction of processing, data portability, and objection to processing.
Our lawful bases for processing your data are: (a) performance of the FermentAdvisor service contract (necessary for the features you request), (b) our legitimate interests in app reliability and abuse prevention, and (c) your explicit consent for optional analytics or personalized advertising where applicable.
To exercise GDPR rights, contact privacy@fermentadvisor.app. You also have the right to lodge a complaint with your local data protection authority.
Children's Privacy
FermentAdvisor is intended for adults 18 and over. We do not knowingly collect personal information from children under 13. If you believe a child under 13 has provided personal information to FermentAdvisor, contact privacy@fermentadvisor.app and we will delete it promptly.
Changes to This Policy
We may update this privacy policy as the app evolves. When we make material changes, we will update the effective date at the top of this page and (where required by law) notify you through the app or by email. Continued use of FermentAdvisor after an update means you accept the revised policy.
Contact
Questions about this privacy policy? Get in touch:
Email: privacy@fermentadvisor.app