Coffee Roasting Operations Monitoring
Continuous T + RH monitoring across green-coffee storage, roasted-coffee aging, and roastery floor — with per-lot environmental records for SCA / Q Grader specialty coffee traceability.
Scope: storage + aging + facility, not real-time roast control
LoopString monitors and controls slow-process variables (storage T / RH, roastery ambient, post-roast aging environment). The real-time roast curve itself — drum temperature, gas pressure, exhaust fan during the 12–15 minute roast — needs faster control loops than Pi-based PID is the right tool for. For roast curve work, use Cropster / Artisan with the roaster's PLC. Use LoopString for everything around the roast.
The Problem
Green coffee degrades in poor storage
Green beans are hygroscopic — too much RH and they go off; too dry and they age fast. A muggy summer week can drop a $4,000 sack to a Q-grade you can no longer sell.
Roastery floor T/RH affects everything downstream
Roastery ambient T + RH drives drum start temperature, post-roast cooling rate, and grind/extraction QA. Tracking it manually leaves gaps; tracking it continuously turns into actionable patterns.
Roasted coffee aging is invisible without records
Roasted coffee degasses + ages in bags + bins; aroma compounds drift over weeks. Without environmental logs you cannot correlate batch QA scores to storage conditions.
SCA / Q Grader audit + traceability
Specialty operations chasing Q-grade scores or chasing SCA certifications increasingly include environmental traceability for green-storage and roasted-aging. Paper logs do not survive an audit.
How LoopString Solves It
Green-storage + roasted-storage climate control
On-Pi PID + threshold logic drives dehumidifier + AC + heater in green storage rooms to hold 50–60% RH at 15–20 °C. Roasted-coffee storage runs cooler + drier.
Roastery-floor dashboard with sparklines
See green storage, roasted storage, and roastery floor T/RH on one screen. Per-batch overlay of roastery ambient at the time of roast — useful when troubleshooting QA scores.
Threshold alerts on storage windows
Configure narrow alert windows on green-storage RH + temperature. Anomaly detection on baseline drift catches dehumidifier failure or cooling-unit degradation weeks before product is hit.
Per-lot environmental traceability
Export PDF reports per green-coffee lot covering its storage window: T, RH, and date range. Useful for SCA traceability claims and for Q Grader documentation.
Built for these coffee operators
Specialty coffee roasters
Green storage room + roasted-coffee aging room + roastery floor ambient monitoring with per-lot environmental records.
Multi-roastery operations
Distributed roastery network with central dashboard + RBAC for facility managers; aggregate environmental records across roasteries.
Green coffee importers + warehouses
Bulk green-coffee warehouses (jute / GrainPro / vacuum) need continuous T + RH monitoring across the storage floor; pair with /use-cases/cold-storage for chilled green storage.
Coffee QA + research labs
Cupping / QA labs with strict ambient T + RH windows for repeatable sensory work; pair with /use-cases/lab for the lab-bench instrumentation.
Cafés + coffee bars (storage room)
On-premise storage rooms for retail bag inventory — RH + temp affect freshness perception over the customer's pour.
Coffee equipment R&D + grinder calibration
Grinder + brewer calibration depends on ambient — track it so calibration logs can be normalised across seasons.
Hardware You'll Use
SHT31
Combined T + RH for storage rooms + roastery floor
I²CDS18B20
Spot temperature probes (bag-level, bin-level)
1-WireRelay module
Dehumidifier + AC + heater control in storage rooms
GPIOCO₂ sensor (optional)
CO₂ off-gassing tracking for freshly roasted bins
UART
Frequently asked questions
- Can LoopString log a coffee roast profile?
- Yes. It samples bean-mass and environment temperature from thermocouple/RTD inputs on the Pi and records the curve so you can compare roasts and reproduce a profile. Sampling continues on-device regardless of connectivity.
- Can it alert me at a target roast temperature?
- Yes. Threshold alerts fire at the temperatures you define, so you get a heads-up during the roast rather than after reviewing the log.
- Does LoopString replace my roaster controls?
- No — it sits alongside them as a monitoring and logging layer, and can drive auxiliary relays (e.g. cooling tray fans). The roaster’s own burner controls stay in charge of the heat.
Ready to log every degree the green sees?
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