Roasting

Agtron meters measure roast color as a 0–100 reflectance score. A gap of 8–10 points between whole-bean and ground readings signals even development.

Roast level drives acid loss, melanoidin buildup, and cell collapse. Agtron quantifies those changes objectively, replacing unreliable visual assessment.

Coffee roasting transfers heat as conduction, convection, and radiation. Shifting the ratio via airflow and gas is how roasters shape body and brightness.

CO₂ in freshly roasted beans disrupts extraction until it dissipates over days. Rest 5–14 days for filter, 7–21 for espresso, to achieve even extraction.

Drum roasters and fluid bed air roasters represent two fundamentally different approaches to applying heat to coffee.

First crack ruptures cell walls; second crack degrades lignin. Drop point determines how much origin character survives into the cup.

Home roasting yields specialty coffee at half the cost of buying roasted. Ventilation, rest time, and batch discipline determine whether results repeat.

Light and dark roasts are distinct flavor vocabularies, not a strength scale. Acid versus melanoidin formation defines the divide, not caffeine content.

Maillard chemistry from ~140°C drives coffee's aroma, color, and flavor complexity. Rate of rise and timing through this phase shape sweetness and body.

Nordic roasting targets 15–20% DTR and drop temperatures of 195–205°C. The result is high acidity, fruit aromatics, and tea-like body over roast flavor.

An omni roast is one profile calibrated to work as both pour-over and espresso. The cost is a tighter window and small concessions on peak expression.

Rate of Rise — the speed at which bean temperature increases per unit of time — is the single most diagnostic metric in modern coffee roasting.

Baked, scorched, tipped, underdeveloped, quakers — roast defects are identifiable, diagnosable, and fixable.

A roast profile is a time-temperature curve; RoR and DTR are the key metrics. Logging software makes profiles repeatable and diagnosable across batches.

Bean density and cell structure vary by cultivar and altitude. Dense beans handle higher charges; soft beans need lower heat and more development time.

Probat, Loring, Giesen, and Diedrich differ in heat-transfer design with real effects on cup character, energy use, and emissions compliance.

A roast optimized for filter typically fails for espresso, and vice versa. Espresso needs 1–2 more DTR points than filter to achieve extractable sweetness.

Natural, washed, and honey coffees enter the roaster in fundamentally different chemical states.

Cropster, Artisan, and OEM platforms each capture roast curves differently. Operation size and sharing needs determine which tool fits a given roastery.

Sample roasting is a light roast that evaluates green coffee before purchase. It reveals cleanliness, acidity, and aromatic potential in the raw material.

Green coffee degrades under heat, humidity, and oxygen even when sealed. GrainPro liners, stable storage, and portioned freezing preserve cup quality.