How it works
This site turns a bag of coffee into a brew profile for the Fellow Aiden, sends it to your brewer, and helps you make it better cup by cup. Along the way it picks up a few ideas of its own: freshness windows, a taste passport, AutoPilot. Here is what each one actually does.
#Reading a bag and the catalog
#How does reading a bag work?
Take a photo of the bag's label and the app reads it: roaster, coffee name, origin, process, roast level, tasting notes, roast date. An AI model does the reading, but that is all it does. It extracts what the label says and never invents brew settings.
By default the read uses only your photo, which keeps it fast and lets you use it right at the shelf in a store. If the label is sparse, the optional "Look it up online" button runs a web search for the same coffee on the roaster's site and fills in what the label left out.
#Where do the brew settings come from?
Not from AI. Every profile is generated by a fixed set of rules that map the coffee's attributes (roast level, process, origin, and so on) to brew settings: temperature, ratio, bloom, pulses. The same coffee facts always produce the same recipe, and every number can be traced back to a rule. The AI's only job is reading labels and web pages.
#How does the catalog work?
The catalog is communal. Every coffee anyone has read in is there, along with its recipes. When a coffee has several recipes, they are ranked by member upvotes: the top one is shown as the recommended recipe, the rest as alternates. A recipe can be marked as improving on another, and you will see a badge when a newer version of a recipe you are looking at exists.
#Can I edit a coffee's details?
Yes, within limits. Any signed-in member can fill in a field that is empty: origin, process, roast level, tasting notes, variety, altitude, description, or a missing photo. Replacing something that is already filled in is reserved for moderators. That split keeps the catalog open to contributions without letting anyone overwrite someone else's work.
#Why does the app sometimes ask me about a coffee's origin or process?
Most seeded catalog coffees are missing details like origin and process, and those two fields are exactly what your Taste Passport is built from. So the app occasionally asks you to fill a gap on a coffee you have bagged or brewed. It only ever asks for fields that matter to everyone: origin, process, tasting notes, and roast level.
If the bag does not state it, tap "Not listed". That is a real answer: it stops the question for you, and once a few members agree, for everyone. You can also skip a question (it rests for a week), dismiss a coffee entirely, or mute the asks altogether from your account page. Muting is reversible. If you do not have the bag at hand, there is a lookup shortcut: Premium members get a one-tap web lookup that proposes an answer with its source shown, and everyone else gets a ready-made web search link. Nothing is saved until you confirm it.
#Your bags and freshness
#How do bags work?
Each coffee you own gets one bag on your shelf. Recording the roast date starts its freshness clock. Buying the same coffee again is a rebuy: enter the new roast date and the clock resets, while your personal notes stay. When a bag runs out, finish it, and the app will ask how you liked the beans.
#How does the freshness timeline work?
Every bag moves through three phases: Resting (still degassing, wait a bit), Ready (the good window), and Tired (past its best). The boundaries are computed per coffee from its roast level, its process, and whether it is decaf. Dark roasts are ready in a few days; light roasts need two weeks or more; fermented and natural coffees need extra rest; decaf fades sooner.
You will see the ready point as a range rather than an exact day, and that is deliberate. Roasters disagree with each other about resting more than roast levels differ from each other, so a range like "about 10-20 days" is the honest claim. If a coffee's roast level is unknown, the app assumes medium (statistically the most likely) and says so, rather than pretending to know.
#What happens when I open a bag?
Air is the main thing that stales coffee, so opening a bag starts a second, shorter clock: roughly three weeks of good drinking once air is in, regardless of what the sealed dates said. Recording the open is free and backdatable, and the app will also stamp it automatically the first time you actually brew from the bag (you can edit or clear that stamp with one tap). Opening never shortens the rest itself: a bag opened early still needs its full rest, it is just staling while it gets there.
#How does freezing a bag work?
Freezing pauses the clock. At freezer temperatures, staling and degassing both slow to a crawl, so the app treats a frozen bag as fully paused: a bag frozen at day 20 thaws at day 20. That also means a bag frozen mid-rest thaws mid-rest and finishes resting on the counter, so the sweet spot is freezing at peak. The open clock pauses too, automatically.
Freeze, thaw, and open dates are all editable after the fact, and a freeze recorded by mistake can be cleared entirely. Mistakes are meant to be cheap. Two practical notes: no thaw penalty exists (a thawed bag simply resumes where it paused, and you can open and brew it right away, since condensation forms on the packaging rather than the beans), and if you grind straight from frozen, go one step coarser, because frozen beans shatter finer.
Freezer tracking is free for everyone. Only AutoPilot acting on it is a Premium feature.
#What is Freshness AutoPilot?
A Premium feature that keeps the recipe on your brewer matched to your bag's age. Coffee wants slightly different treatment across its life: a longer bloom while it is still degassing, then a small temperature lift as it ages toward tired. AutoPilot computes that adjustment from your bag's effective age and pushes the updated recipe to your Aiden, so the profile you select is always tuned for today's beans.
It manages your existing device profile in place rather than cluttering your brewer with copies: the first push adopts the recipe already on the device and renames it so you can tell it is managed, and turning AutoPilot off restores the original name. It pauses while the bag is frozen, respects the shorter clock of an opened bag, composes with your dial-in adjustments, and retires itself once the bag is past its window or finished. The freshness math itself is visible to everyone on the timeline; AutoPilot is the part that acts on it for you.
#Dialing in and recipes
#What happens when I send a profile to my brewer?
The profile is written to your Aiden through your Fellow account, and the send is recorded as a brew. On a later visit (between two hours and ten days after), a small banner asks how it was: Great, Good, or Off, one tap. That answer feeds your stats and your taste profile. The banner is polite: it can be snoozed, and after two dismissals it stops asking about that brew.
#What is a taste check-in?
If a brew was off, you can say how: sour, bitter, weak, harsh, and so on. The app turns that into one concrete change, using fixed rules: sour lifts the temperature and lengthens the bloom, bitter lowers it, weak pulls the ratio stronger, harsh drops a pulse. Only the most telling defect is acted on, because changing one thing at a time dials in faster, and the rest are noted for your next brew. Contradictory answers (both bitter and sour) cancel out rather than the app guessing a direction.
Grind is never changed for you, since the app cannot turn your grinder. Where grind is the real fix, you get a plain-language tip alongside the change. The adjusted recipe is minted as your own v2. Brew that, check in again, and the versions chain until it tastes right.
#What is the difference between my personal profiles and catalog recipes?
Everything you dial in stays yours. Adjusted versions live in your personal space as a v1, v2, v3 chain, and nothing there is ever published automatically. If a version turns out great, you can contribute it: that publishes a snapshot copy to the catalog for everyone, optionally marked as improving on the recipe you started from. Your personal chain stays private either way.
#What is the Dial-In Coach?
A Premium guide through the dial-in process. Instead of changing several things at once, the coach picks the single most promising lever for your situation (ratio, temperature, or pulse structure), explains in plain words why that lever and what to expect in the cup, and waits for your next brew before suggesting the next step. The numbers come from the same deterministic rules as everything else; the coach adds the explanation and the one-step-at-a-time discipline.
#How do grind settings work with my grinder?
Grind size is stored as microns, a grinder-neutral measure, and translated to your specific grinder's dial at display time. Register your grinder (there are a few hundred models in the list) and every recipe shows the setting in your numbers. For coffees from Fellow's official drops, where Fellow published the exact dial range they used on a given grinder, you will see that verbatim with a "Fellow" badge instead of an estimate. Free accounts have one registered grinder; Premium lets you register several and see a grind line for each.
#Ratings and your Coffee Journey
#How do ratings work?
Two separate signals, on purpose. A coffee rating is 1 to 10 on the beans themselves: would you buy this coffee again? A brew sentiment (Great, Good, Off) is about a single brew: did this cup work? A great coffee can produce a bad cup while you are dialing in, and the app keeps those apart. Ratings are private, always free, and you can change them anytime. If you have not rated a coffee, your brew sentiments stand in as a rough signal until you do.
#What is the Taste Passport?
A map of where your brewing has taken you: which origins, processes, and roast levels you have actually brewed, which coffees you loved, and what tends to go wrong. Each origin and process you brew earns a stamp. Coffees you rated but never brewed still count as taste anchors, but only brewed coffees earn stamps: the passport records where you have been, not what you have looked at. This is also why filling in a coffee's missing origin or process pays off directly: no attributes, no stamp.
#What is the Coffee Journey?
The Premium layer that turns your data into words. It has a few parts: a per-coffee "read" that explains what a specific coffee's origin, process, and variety mean for the cup and how it sits against your taste; a journey narrative that tells the story of your brewing so far, where you have been, what stands out, what to try next; and a flavor glossary behind the tasting-note chips. It needs at least three distinct brewed coffees before it has enough to say.
Everything it writes is grounded in your own passport, and you can check that: the "What is this based on?" toggle under the narrative shows exactly the facts it was given, nothing more. It never invents coffee attributes and never produces brew numbers, since those come from the deterministic engine. Your private bag notes inform the narrative but are never quoted back. Free members see a personal teaser built from their own stats instead: the facts are free, the interpretation is Premium.
#How do recommendations work?
Rule-based matching, not AI. The app scores unbrewed catalog coffees against the ones you rated highly, weighing shared origin, process, roast level, and overlapping tasting notes, and shows you two lists: coffees like what you loved, and a "stamp a new page" pick that would add a new stamp to your passport. Every pick comes with its reason spelled out ("Washed, from Ethiopia, like a coffee you rated 9"). Free members get one full pick; Premium gets both lists.
#Devices, stats, and account
#Is my Fellow account safe with you?
Your Fellow password is encrypted the moment it arrives and stays encrypted at rest, with the encryption keys themselves protected by a hardware-backed key vault in production. It is used for exactly one thing: talking to Fellow's servers on your behalf to push profiles, read your brewer, and manage schedules. It is never shown, never logged, and never used for anything else. If decryption ever fails, the app treats it as a failed login rather than guessing. The privacy policy has the full picture.
#How does brew tracking work?
Fellow's cloud does not keep a brew history, only lifetime counters on the device. So for Premium members the app checks those counters every hour and turns the differences into brew events: every brew counts, scheduled ones included. There is no toggle and nothing to remember. If polling was interrupted for a long stretch, the app re-baselines instead of inventing a flood of catch-up brews, and if your Fellow login stops working, tracking pauses and tells you on the stats page until you re-register.
#What do My Stats show?
Headline counts and your brew streaks are free. The full picture (brewing heatmap, patterns over time, tracked liters) is Premium. Streaks and the heatmap follow your local clock, so a late-night brew lands on the right day. The page also reads your Aiden's lifetime odometer live from the device: total brews and total water through it, ever.
#How do brew schedules work?
Premium members can manage the Aiden's scheduled brews from the site. The device itself is the source of truth: the app stores nothing and reads your schedules live from the brewer. One honest caveat: Fellow's system has no way to edit a schedule, so changing a time or day works by removing the old schedule and creating the corrected one. Schedules that point at an AutoPilot-managed profile are badged so you know that recipe adjusts itself.
#What exactly does Premium include, and what stays free?
The rule is: the facts are free, the interpretation and the automation are Premium. Free forever: the whole catalog, bag reading, profile generation, sending to your brewer, the dial-in loop, ratings, bag tracking with the full freshness timeline, freezer and opened-bag tracking, one grinder, and headline stats. Premium adds the layer on top: the Coffee Journey (decodes, narrative, glossary depth), full recommendations, Freshness AutoPilot, the Dial-In Coach, automatic brew tracking, full stats, brew schedules, multiple grinders, and the catalog lookup shortcut. There is one free trial per account; plans and prices are on the Premium page.
Still wondering about something? Ask me directly and the answer will probably end up on this page.