Coffee Roasting     RoR flatline end of Maillard phase

2025-07-21 07:25

RoR flatline end of Maillard phase

Hey all,

I have noticed on some of my most recent roasts my RoR flatlines towards the end of Maillard phase and then continues its decline. I am wondering what exactly this does to overall coffee development and is there something I should change? I attached a picture of a recent roast and added my gas and fan setting adjustments.

400 Charge

1 minute soak

Fan = 50 (Low)

2.2kpA = Gas

75 (dial) = Drum

@ 300 Fan = 54 (Medium)

@ 355 Gas = 1.8kpA

@ 365 Fan = 58 (High)

@ 370 Gas = 1.2kpA

45 sec after 1st Crack Gas = .8kpA

1 minute after 1st Crack Gas = .5kpA

14.6% development

Bean Density: .68g/ml

Bean Moisture: 11.9%

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2025-07-21 10:39

Hey @Slimfl08

How does the cup taste? I am guessing this is a light or even light-medium roast level.

I see nothing wrong with a flatlin in your RoR. The way this reads is, "you are moving at this speed consistently." Like cruise control on the highway. The only aspect to give SLIGHT paust to is the increase in the IT (blue) where a minute before you flatline it increases to show a potential buildup in momentum. I say slight, because your RoR does not increase, and your ET (orange) is trending down.

If the cup tastes good, great! If you're curious to see what happens if it is not flatlining and maybe unlock more flavor, move your 355F gas adjustments from 1.8 to 1.4 instead. This should keep RoR sloping if that's what you are concerned about. If that doesn't do the trick, then move it to 1.2 on the roast of that that.

Happy roasting!

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2025-07-22 06:30

@bryantscannell

Thanks for the response as always! Cups have been good and yep, light medium I would say on this one. I posted as I am interested in determining ways to correct it if it was of concern, but it seems like not too big of a problem as long as my BT is moving in the right direction. I am always up for learning more and making the fine adjustments to get the best roast I possibly can.

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