Tuesday, May 26, 2020

Roast Comparator

While Artisan always allowed to load a second profile into the background, sometimes you want to compare the shape of more than two profiles. For this we introduced the Ranking Reports already in 2016 which allows to produce a nice Web page containing, next to sortable tables with the key data points of the selected roasts, a chart of all selected profiles. The drawback of this approach is that the report is static in that it is not possible to apply ad-hoc changes to navigate the representation. The Comparator allows to compare profiles dynamically.

The Comparator is in many ways similar to the Web Ranking Report, each having its own advantages and purpose. The Comparator allows to add and remove curves in real time, to pan and zoom over the chart, to realign w.r.t. a different roasting event, to hide and show data just from selected profiles and curve types, like the rate-of-rise curves or special event lines.

The Comparator is especially useful to compare curves from roasting similar or identical beans.  One can analyze how changes in gas or air application affect the BT rate of rise for instance.  It is very useful to see the consistency across several roast batches.  This is a great tool to evaluate your between batch protocol when roasting several batches of the same bean. Commercial roasters can use this as one more QC check on their roasts over time.  It is also useful to compare roasts of the same bean from one year's crop to the next.  Not much value for comparing a natural Ethiopia to a washed Colombia!

Artisan includes many useful tools to improve your roasts. The Analyzer is great for analyzing one roast.  Viewing a profile against a background template is good for comparing two roasts.  The Comparator described here is for deep analysis across multiple roasts.

Getting Started

You start the Comparator mode by selecting its entry under the Tools menu and choose a set of profiles to be compared. If a profile or a background profile is loaded on starting the Comparator, it is started with those profiles. At any time more profiles can be added or profiles can be removed from the session. Selected profiles are rendered on the main Artisan window which shows only the graphs navigation tool bar. Panning and zooming is enabled.

Tool Window

The Comparator is operated using its tool window. In its center it shows the list of profiles that are currently compared. This list can be extended using the Add button and selected profiles can be removed using the Delete button or alternatively by pressing the delete or backspace key. A profiles batch number is rendered as row header, if available, otherwise an automatically generated number is used to identify the profile for this session. Each profile is assigned a color used to draw its curve and a flag to completely hide all curves of a profile. The profiles title is editable, but changes will not be written back to the corresponding profile. Instead this feature serves to make temporary notes and marks.

The two popups on top of the tool are used choose the curves to be displayed per profile and the last popup underneath specifies the event used to align the profiles to each other on the time axis. The alignment is always with respect to the first profile entry in the list to which also the time axis adjusts. If profile lacks the selected alignment event its entry in the list is greyed and the profile is not rendered.

The order of the list also defines the order for drawing the lines. The entries earlier in the list are drawn on top of the entries later in the list. The order of profiles can be changed via drag-and-drop by grabbing the entries via their row headers.

Events are rendered by small round markers on the main temperature curve of a profile (either bean temperature, BT, or environmental temperature, ET). A click on such a mark shows type, time and temperature of that event in the message line. Only one custom event type can be rendered as plain step line.

If profile rows are selected in the tool, all other profiles get rendered in grey scale to highlight the selected ones in the chart. A double click on a profile row header opens the corresponding profile in a second Artisan instance running in Viewer mode for further inspection.

Configurations and Tools

The Comparator has no further configuration options. However, the general curve configurations are also respected by the Comparator. This includes graph rendering options incl. curve style, smoothing and limits, (draggable) legend state, path effects settings, text font and style choices and the general canvas dpi resolution.

The axis limits as configured under menu Config >> Axis are respected as well. It is advisable to set the time axis to automatic adjustment. If Auto is ticked, the Comparator will ensure that all lines are always fully in view. If profiles with wide varying ranges of the rate-of-rise maximum values, it is advisable to check the ∆ET and/or ∆BT flags in the ∆ Axis section to have the maximum limits of the rate-of-rise axis be adjusted automatically as well.

The standard Artisan tools to navigate a profile graph like panning and zooming as well as the cross-lines feature are enabled in the Comparator mode too. The Save Graph actions under menu File allow to export the graph in various file formats and direct printing is enabled as well.


  • a maximum of 10 profiles can be loaded
  • file double-clicked in the macOS Finder or Windows Explorer while Artisan is in the Comparator mode are added to the list
  • sets of profiles can be loaded from zip files as well
  • profiles are be loaded on drag-and-drop on the Comparator tool window too
  • a profiles metadata is shown in a tooltip on hovering over its title in the tool window