![]() Optimally, we want these changes annotated automatically so that they are accurate and consistent. These call-outs give us additional information for post-roast analysis by indicating what control changes the operator made at any given point. In the image above, there are call-outs above the ET that indicate power changes (in blue circles) and fan changes (in gray boxes). Often a profile can indicate control changes made by the operator. The brown band indicates the third phase 2:14 in duration or 19.6% of the entire roast. The yellow band indicates the second phase 4:04 in duration or 35.7% of the entire roast. The green band indicates the entire first phase 5:04 in duration or 44.5% of the entire roast. Additionally, all three phases are labeled by the colored bands across the top of the profile, along with the length of time of the phase, its percentage of the overall roast, and its Roc. This visualization method makes it easier to analyze the roast later, by clearly differentiating the third and final phase (sometimes called the roast development or RD phase). In this profile, the third phase is highlighted by the yellow, vertical band. In the top-left corner of the profile is the legend, indicating which measurements are of which color. I have a third ET measurement labeled as ‘Element’ that is too high in temp to be displayed on these graphs (read about the placement of this thermocouple here). In the profile above, I have displayed two disctinct readings of the environment temperature (ET and ET2) as well as BT and also the rate of change (RoC, labeled as ‘DeltaBT’ in the profile). At a minimum the profile must display the bean temp, but can display as many temps as the machine can measure. Temperature is typically recorded on the Y-axis and time is recorded on the X-axis. ![]() Reading a profileĪ roast profile is a graphical depiction of the roast progression, displayed as temperature over time. As the BT rises, we pass through different phases of the profile, which helps us to conceptualize what is happening inside the beans and that helps guide how we manipulate and control the machine. The three horizontal, colored bands correlate to the three phases based on the bean temperature (BT), which is how we differentiate the phases. ![]() Artisan Roaster Scope is one of the more popular, free apps. Most profiling software on the market, especially the more popular ones have the ability to visually distinquish the three phases. It could be argued that it isn’t even the most important thing we’re worried about at that point in the roast (momentum possibly being more important). Drying doesn’t just happen in the first phase and it isn’t the only phenomenon happening during the first phase. Some have argued that we should just call them the first, second, and third phase for clarity and I would agree with that (Rao, 2014). The third phase (sometimes called the roast development phase or RD).The second phase (sometimes called the Maillard phase or the ramp).The three phases are very commonly referred to as: Across the industry, it’s standard to talk about three phases but the names of the phases differ and are slowly evolving. To help understand what’s going on inside the roaster as well as to communicate with other operators about our roasts, we break it down into three phases. ![]() ![]() Understanding a coffee roasting profile is one of the first skills a new operator should obtain and luckily, profiles are relatively easy to understand! The phases of a roast ![]()
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