class: inverse, center, middle #SCA Roasting Foundation Study Guide, v1.0 .footnote[ Press "h" for keyboard shortcuts for this presentation] --- class: inverse, center, middle ## How to use this guide? Print a copy of [the notes](/docs/foundation-study-guide.pdf) As you progress through the slideshow, fill in the blanks and solve the problems in the notes Study your notes (including familiarizing yourself with the keywords) Bring your completed notes to class and add to them. We'll be handing out the same notes in class! Pass the test like a boss --- class: center, middle name: roaster-diagram # Know thy roaster!  --- layout: true class: center, middle # Three Burner Types --- Atmospheric burner (gas burner) Electric burner (like toaster oven) Infrared burner (ceramic plates in BBQ grill) --- Atmospheric burners are fast and responsive This can be both good and bad; fast = easy to overcompensate --- Electric burners are good below 12kg capacity Slow to respond; are like steering a boat (think drift) --- Infrared burners are energy-efficient But also slow to respond. Gas heats another material (often ceramic) which in turn heats the environment. Deidrich uses IR burners --- layout: false # Heat Transfer Methods <br/><br/><br/> .center[ Convective Conductive Radiative ] --- .left-column[ ## Convective ] .right-column[ * Air as a medium or vehicle * Most common transfer method in drum and air roasters * The greater the temp difference between air and bean greater the transfer (potential) ] --- .left-column[ ## Convective ## Conductive ] .right-column[ - Physical contact + temperature gradient - Common cause of roast defects - Temperature gradient inside bean - Water content is critical.red[\*] ] .red[\*]Water in the bean helps conduct heat from the outside to the inside of the bean. --- .left-column[ ## Convective ## Conductive ## Radiative ] .right-column[ * Electromagnetic radiation (same as the sun) * Some visible, some not * Example: light from heat source, heat felt near a heat source * Metal in roaster acts as a battery, storing energy as heat * Especially the drum, backplate, and faceplate ] --- # Roasting Plant Safety **Three areas of concern:** Fire Ventilation Personal safety * Create an emergency plan ahead of time * Discuss the plan with everyone * Create a cleaning + maintenance plan * Regularly review procedures and plans --- .left-column[ ## Safety Definitions ## Fire Safety ] .right-column[ Keeping your equipment, staff, products, and customers safe from fires. ] --- .left-column[ ## Safety Definitions ## Fire Safety ## Ventilation Safety ] .right-column[ Keeping your staff and customers safe from dangerous gasses and airborne particles (such as dust from green coffee or micro-fibers from jute bags). ] --- .left-column[ ## Safety Definitions ## Fire Safety ## Ventilation Safety ## Personal Safety ] .right-column[ Keeping your self and your staff safe and free from harm or injury ] --- class: center, middle # Roaster fire hazards  --- # Roaster fires What to do: 0. Stay calm 1. Shut off gas (or heating element if electric) 2. Shut off exhaust fan and close exhaust damper if possible 3. Keep drum rotating 4. Use water hose or quenching system if you have it (pulse 10 seconds on, 10 seconds off) 5. Don’t eject beans 6. Monitor the bean temp 7. If you have an afterburner, leave it on 8. If stirer arms are on, turn them off 9. If cooling fan is on, turn it off 10. Extinguish any fire outside drum 11. Don't drop the beans until the BT is below 93°C/200°F 12. Call the fire department when necessary ??? Oxygen is a fuel source. By opening either door to the roaster drum, you will inject more oxygen into the drum. If the beans in the drum are on fire, keep them in the drum where the fire is contained (the drum is fireproof). .footnote[ List adapted from Marty Curtis's list] --- # Personal Safety Concerns **Four areas of concern:** * Green coffee storage * Roasting * Packaging, production * Shipping What are some concerns in these areas? --- # Fire Classifications * Class A Ordinary items (wood, paper, plastic, rags) * Class B Flammable Liquids * Class C Electrical equipment --- # Roaster Cleaning & Maintenance * Remove chaff often (fuel source for fire) * Know where chaff collects in your roaster * At least daily, more for “chaffy” beans * Keep ducts clear/clean (creosote & chaff) * Keep moving parts lubricated (food grade grease) * Follow manufacturer’s manual and recommendations --- # Physical changes in the bean * Dries out * Progressively darkens * Becomes increasingly brittle * First Crack * Size can increase 30 - 100% * Second crack * Eventually oil seeps out (especially beyond second crack) * Sometimes get divots (can be a roast defect) * Rapid cooling (≤ 4min) to halt chemical reactions (changes) --- # First Crack and Second Crack * Every *successful* roast has a first crack * First crack is the result of rapid release of pent-up vapor/steam pressure and CO2 * Not all roasts reach second crack (operator’s preference) * Exothermic flashes as escaping heat affects environment --- # Roast Data Measurements that can be collected from green and roasted coffee: 1. Green: batch weight 2. Green: bulk density 3. Green: volume 4. Green: screen size 5. Green: moisture content (acceptable range for Specialty?) 6. Roasted: color 7. Roasted: weight\* 8. Roasted: bulk density\* 9. Roasted: volume\* Cupping data should be associated with roast profile for post-roast analysis. .footnote[ \*Calculate percent changes for these attributes] --- # Label the following on a typical roast profile Charge, Turning Point, Color change: green to yellow, First crack, Second crack, Roast End  --- # Roast Progression **Generally speaking:** * Lighter roasts highlight (preserve) acidity, enzymatic flavors/aromas * Darker roasts emphasize chocolatey, nutty, bitter flavors/aromas **Why?** As the roast progresses, organic acids are broken down. Also, with darker roasts, the Maillard reaction has more time to react. The flavors most associated with the Maillard reaction are *chocolatey, nutty, and bitter* flavors and aromas. --- # Temperature Midway Point ≈ 75 Agtron * New concept * Generates easy color to work/train with * Not meant to be a standard or a sweet spot regarding end product  --- class: center, middle End of presentation