
zerobrew: coffee dial-in
Fix sour or bitter espresso
0 ratings
Free
In-App Purchases
Rating summary
About
Your coffee tasted sour again. Or bitter. And you have no idea what to change: the grind, the water temperature, the ratio, the time.
Most people change three things at once and hope. zerobrew replaces the guessing with one clear instruction.
HOW IT WORKS
1. Log the brew: dose, yield, time, grind setting, water temperature.
2. Say how it tasted: sour, balanced or bitter.
3. Get the fix. Sour means under extracted, so grind finer. Bitter means over extracted, so pull less out. One change, not five.
4. Brew again and tell zerobrew whether it worked. The next suggestion is built on that answer.
Sour is under extraction. Bitter is over extraction. zerobrew reads your numbers next to your taste note, then tells you which knob to turn and in which direction.
WHAT YOU GET
Dial-in coach on the home screen, ready before your first tap
Taste diagnosis (sour, balanced, bitter) with a concrete next step
Advice that remembers: if a change worked, the next move gets smaller, and if the cup got worse, the direction flips
Guided first brew that walks you from bean to diagnosis
Brew log for dose, yield, time, grind setting, water temperature and rating
Bean shelf with roast dates and freshness, from resting to past peak
Grinder tracking, so every grind setting stays tied to the right grinder
Brew scores, streaks and achievements
Shareable recipe cards with the diagnosis badge
Starter recipes and a short setup quiz, so your first recipe already fits your gear
Step by step brewing guides for every method
METHODS
Espresso, V60, AeroPress, Chemex, French press, Moka pot and cold brew.
FREE AND PRO
Free every day: one brew log, up to three beans, the brewing guides, the starter recipes, and your first dial-in fix shown in full with its steps.
zerobrew Pro adds:
Unlimited brew logs and beans
Every dial-in suggestion, on every brew
What changed between your best and your worst brew, side by side
Insights: trends over time, method breakdown, top beans
CSV export of your whole brew history
Pro comes with a 7 day free trial. Monthly, annual and lifetime options.
PRIVATE BY DEFAULT
No account, no sign up, no cloud. Your beans and brews stay on your device.
Coffee gets better when you stop changing five things at once. Log one brew, taste it, change one thing.
Privacy Policy: https://greeneyeapp.com/en/legal/zerobrew-privacy
Terms of Use (EULA): https://greeneyeapp.com/en/legal/zerobrew-terms
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What's New in zerobrew
2.0.0
September 1, 2026
2.0 turns zerobrew from a brew log into a coach. - Dial-in coach on the home screen: last brew, taste and next move, one tap away - Guided first brew, from bean to diagnosis - Advice that looks back: smaller step if it worked, reverses if the cup got worse - Best vs worst brew, side by side (Pro) - Share cards now carry a diagnosis badge
MoreSubscription plans
zerobrew Pro Monthly
All Pro features. Renews monthly.
$4.991 Month
1
In-App Purchases
$49.99
zerobrew Pro Lifetime
All Pro features. One time, forever.





