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The roast plan

Artisan does / TilauScope adds

Artisan does — lets you load a previous roast as a background curve and try to follow it by eye. Which reference to use, and whether it was any good, is left entirely to you.

TilauScope adds — a plan computed for this coffee, this batch size and this machine, with milestone targets, phase durations, a staged heat profile and a projected DTR. Every value states where it came from, and the ones derived from your own previous roasts of the same coffee say how many roasts are behind them.

Where the plan lives

The plan is not a screen inside TilauScope. It is produced in BeanCave → Roasting plan, a short step-by-step form: pick the coffee, enter the parameters, adjust probe offsets if needed. The batch weight and roast level come back as you last left them, since a bag is usually worked through at one batch size and one roast level over several sessions. The ambient fields do not: they describe the room as it is now, and are filled from the online weather or the ambient probe. Two actions close it out:

  • ⚡ Generate Roast Plan — becomes available only once every required field is filled, and produces a PDF. That document is the plan: everything described below is in it.
  • Inject in Artisan — writes the plan's phases and alarms into Artisan, so the roast is set up before it starts. TilauScope confirms with The base of the roasting plan, phases and alarms have been injected into Artisan. Get ready to roast!

The same engine also feeds the Predicted targets and STRATEGY blocks on the ROAST SETUP sheet, which is why those predictions and this PDF agree with each other.

The plan prints in the language TilauScope is set to, whichever alphabet that language uses: Greek, Cyrillic, Chinese, Japanese, Korean, and Arabic, Persian or Hebrew read right to left. Coffee and farm names print in their own script too. Thai is the one exception — it has no letterforms available and prints blank.

What the plan contains

The coffee and the batch. Bean Name, Weight to roast, Roaster, Target Agtron Profile, plus the coffee's own properties — Density, Bean Humidity, Process Type — and, where an ambient probe is fitted, Ambient Temp and Ambient Humidity. A plan is specific to a batch on a day, not to a coffee in the abstract.

Milestone targets. Charge Temp, End of Dry Temp, First Crack Temp, First Crack Time, Drop Temp.

Phase durations. Dry Phase Time, Maillard Phase Time, Development Phase Time and Total Time — a target per phase rather than one figure for the whole roast. Two of them have a floor that comes from the machine rather than from the style: drying is never planned under 4:30, Maillard never under 3:00. Below those the roast is not reachable on a drum of this size — the first belongs to sample roasters, the second would mean heating hard enough to scorch the bean. When a floor applies, the total extends; no other phase is shortened to pay for it.

RoR targets. Target ROR Maillard, Target ROR at FC, Target ROR Dev and Target ROR at Drop: the slope to hold at each stage. The Maillard figure is an average, and an average says nothing about where the roast lands — Target ROR at FC is the arrival value, worked out from how quickly this machine's rate of rise decays, and it is the one that decides first crack.

Development. Resulting DTR (%) — development itself is planned as a duration at the right temperature and rate of rise for the batch, and the ratio is the figure that comes out of it, known before charging rather than discovered at the end. When it falls outside the usual range for the roast level, the plan notes it as a sign to look at the front of the roast, not at development.

The curve. Planned BT and Planned RoR, a smooth curve the real roast can be laid over.

The heat profile. Heater and Heater ramp (anticipated) — the reductions are planned before first crack, not applied after it, down to last step {n} s before FC. This is the difference between a heat cut that controls first crack and one that arrives too late and flattens the curve.

Before dry end the ladder normally does nothing: a charge temperature and an initial heat that suit the coffee carry it through drying untouched. When they do not — when this coffee has shown a rate of rise that flattens too early — you bring the burner down during drying to put the curve back on a slope. The plan learns that from your own roasts rather than inventing it: when it starts, how large your steps are, and the value you land on at dry end. A coffee you have never had to correct gets no reduction scheduled at all.

After dry end the ladder descends, but never below what the coffee needs to keep Maillard running. That demand is read from the batch itself — its process first, then variety and origin, then density, moisture, water activity and the room the machine is breathing — and it holds the heat up through the whole phase, releasing by one step only at the end, shortly before first crack. Washed coffees carry the highest demand and hold it longest; naturals and fermented lots have had part of their sugars broken down already and sustain themselves earlier. The development setting is reached after first crack, never before it — arriving at it early is the classic way to produce a baked cup while the curve still looks correct.

Machine settings at phase entry. A table of what each lever must read as a phase begins: at charge, when bean temperature reaches dry end, and at first crack. Not an average for the phase — an average is not a setting anyone dials, and treating one as an instruction puts the middle of the descent at the start of the phase. Expect the burner to show the same value at charge and at dry end: the drying fire is held through dry end, and the descent starts just after it.

The control ramps, on their own page. The heat ladder used to be a run of value @ temperature pairs — exact, unreadable while roasting. It is now a chart plus a checklist. The chart draws the whole roast with burner in red and airflow in blue, the drying, Maillard and development bands behind them, the dry-end and first-crack marks, and the value each lever finishes on in the right margin. Each level is a step held until the next change, because that is what the plan asks for — one move, then time to read its effect, never a continuous slide. Below it, every gesture in order: its time, the bean temperature that triggers it, which lever, and from what to what. Then At a glance — charge and drop temperatures, first crack, total time, and the duration of each phase with its share of the roast.

Airflow. Airflow, AirWave, AirWave Mode, with the reason attached — to smooth RoR, to prevent crash, Action: Increase extraction/airflow to shed thermal energy.

Drum speed. Drum Speed and Control, computed once for this batch — see Preparing a roast for why drum speed is a setup decision.

Action notes. Each requested gesture comes with its reason (Action: Reduce burner 10% 45s before, Action: Boost heater). A plan you understand is a plan you can learn from; a list of orders is not.

Risk markers. CRASH and FLICK points with a Severity, plus RoR variance — the plan knows where this coffee is likely to crash or flick before it happens.

Setup conflicts. Sometimes the roast being asked for cannot be held, and the plan says so rather than printing numbers that will not work. Three cases: the rate of rise would have to climb through Maillard instead of falling — too much temperature to cover in the time, and a flick is certain; it would have to collapse before first crack — a flat, baked cup; or the burner would have to come down faster than five percent every thirty seconds, which is the point past which you can no longer see what a change did. In all three the plan names the setup that caused it and stops there. It does not invent a correction: a chain reaction is not recovered once it has started, and the answer belongs to the next roast — a different charge temperature, a different initial heat, a different planned Maillard.

Note

Every temperature in the plan is a bean temperature and every duration is in minutes and seconds. The PDF states this, and it also restates the target Agtron profile the plan was computed for, so a printed plan cannot be misread later.

Where each value comes from

This is the part that distinguishes the plan from a reference curve: it never hides whether it is speaking from your experience or from a reference table.

Alongside the values, the plan carries First Crack source, Heater source, Phase timing source, Drop RoR source and Drop Temp Source. Each reads either learned (n=N) — derived from N of your own roasts — or a reference value, or a blend of the two. Above them sits Plan confidence, in plain words:

Plan confidence Meaning
high (consistent history) Enough of your own roasts, and they agree with each other.
medium (partial history) Some history, not enough to lead on everything.
low (grid) Reference values. This coffee is new to the machine, or too few roasts exist.

A first roast of a new coffee is honestly labelled low confidence. That is not a defect — it is the plan declining to pretend.

Which previous roasts count

References are drawn only from roasts of the same coffee — matched on its BeanCave identity, not on a similar-looking name — and at a comparable batch size. A 250 g roast is not used as a reference for a 450 g one, because it never was one. This is what stops a plan from being steered by a curve that had nothing to do with the batch in the drum.

What the plan learns, and when

Learning is not a single switch: each quantity has its own threshold, and until it is met the plan uses reference values for that quantity alone.

What is learned From when
First crack temperature From the 3rd roast of the same coffee. At 2 roasts, your measured value and the reference are blended.
First crack corrected for batch size Needs 3 roasts with both first crack and charge weight recorded. Removes the bias that comes from comparing different batch sizes.
Phase durations From the 2nd roast; carries full weight from the 3rd.
Heat profile and development ramp From the 2nd roast.
Drop temperature, from colour feedback Progressively, as measured colours accumulate — the colour you record at the end of a roast corrects the next plan's drop target.
RoR at drop From your own recorded roast endings.

So the second roast of a coffee is already better informed than the first, and the third is where the plan genuinely starts speaking from your machine.

What the plan learns without showing it

Two things are learned but not printed: the expected RoR peak for your machine (from the 2nd roast, and discarded if it falls outside a sane range, so one freak roast cannot poison it), and your probe offsets (from four measurements onward). They are mentioned here so that nothing in the plan's behaviour is unaccounted for.

Guardrails

Learning is bounded. Values that fall outside professional roasting ranges are rejected rather than adopted, and where a learned figure is implausible the plan falls back to the reference and says so through its source labels. A single bad roast does not move the plan; a consistent habit does.

If the request itself cannot be met — a target that no plan could reach for this coffee and this batch — the plan says OUT OF SCOPE instead of drawing a curve that cannot be followed.

Tip

A roast you know went wrong can be excluded from learning altogether, from the assistant at the end of the roast. Use it: the plan is only as good as the roasts it believes.

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