Barista Camp 2015 | Christian Klatt — Heating (in) grinders

The focus lies on the grinders. Consistency is key, predictability for accurate brewing of the defined recipe the aim. Besides dose and particle size, there is the “invisible” parameter heat that influences the shot/brew and is widely misinterpreted. Where does the heat in grinders come from, where does it go and what does it do to the coffee?

Transcript

1. HEMRO GROUP Heating (in) Grinders
2. 10.09.2015 2 Agenda BEVERAGE GRINDER COFFEE
3. 10.09.2015 3 Agenda BEVERAGE GRINDER COFFEE
4. 10.09.2015 4 Heat Development In Ground Coffee Heat comes from: • Motor (+ grind chamber & discs) • Breaking of beans • Friction between ground coffee particles • Friction with grind chamber • Friction with grinding discs
5. 10.09.2015 5 Heat Transfer Into Ground Coffee • Heat transfer into the coffee and out of the system
6. 10.09.2015 6 Heat Transfer Into Ground Coffee • Heat transfer into the coffee and out of the system • The longer between shots, the more heat is transferred
7. 10.09.2015 7 Heat Transfer Into Ground Coffee • Heat transfer into the coffee and out of the system • The longer between shots, the more heat is transferred • The slower the motor, the longer the dose, the hotter the motor
8. 10.09.2015 8 Heat Transfer Into Ground Coffee • Heat transfer into the coffee and out of the system • The longer between shots, the more heat is transferred • The slower the motor, the longer the dose, the hotter the motor • The more ground coffee in the grinder, the more heat is transferred
9. 10.09.2015 9 Temperature [°C] Time [h] Heat Development in Grinders Motor (idle) Idle operation (without grinding coffee)
10. 10.09.2015 10 Temperature [°C] Time [h] Heat Development in Grinders Motor (idle) Grind chamber (idle) Idle operation (without grinding coffee)
11. 10.09.2015 11 Temperature [°C] Time [h] 1 2 Heat Development in Grinders Motor (idle) Grind chamber (grinding) Grinding Motor (grinding) Grind chamber (idle)
12. 10.09.2015 12 Temperature [°C] Time [h] 1 2 Heat Development in Grinders Grind chamber (grinding) Grinding without ventilation Motor (grinding)
13. 10.09.2015 13 Temperature [°C] Time [h] 1 2 Heat Development in Grinders Grind chamber (grinding) With ventilation Motor (grinding) Motor (ventilated) Grind chamber (ventilated)
14. 10.09.2015 14 Temperature [°C] Time [h] 1 2 Heat Development in Grinders With ventilation Motor (ventilated) Grind chamber (ventilated)
15. 10.09.2015 15 Temperature [°C] Time [h] 1 2 Heat Development in Grinders With ventilation Motor Grind chamber
16. 10.09.2015 16 Temperature [°C] Time [h] 1 2 Heat Development in Grinders Slower motor (lower rpm) Motor (slower rpm) Grind chamber (slower rpm)
17. 10.09.2015 17 Advantages from Ventilation Cooling of motor: • Higher cycle possible K30: 2 double shots /min K30 Air: 4 double shots /min PEAK: 6 double shots /min Cooling of grind chamber: • More consistent grind adjustment • More consistent coffee temperature • More consistent extraction
18. 10.09.2015 18 Agenda BEVERAGE GRINDER COFFEE
19. 10.09.2015 19 Influence of Heat In Coffee Grounds What does not happen when grinder heats up: • Grind chamber expands • Bigger gap between the burrs • Coarser grinding
20. 10.09.2015 20 Influence of Heat In Coffee Grounds What does not happen when grinder heats up: • Grind chamber expands • Bigger gap between the burrs • Coarser grinding What happens when grinder heats up: • Aggregate states of coffee bean substances change • Coffee bean gets more malleable / pliable • Brewing behaviour “like coarser grind”
21. 10.09.2015 21 Influence of Heat In Coffee Grounds
22. 10.09.2015 22 Influence of Heat In Coffee Grounds
23. 10.09.2015 23 Agenda BEVERAGE GRINDER COFFEE
24. 10.09.2015 24 Influence of Heat In Coffee Grounds What happens when grinder heats up: • Faster blunt shots • More bitter, week, (diluted) • Less strength, higher extraction How to countersteer: • Adjusting finer, to lengthen the shots again • Lower the brewing temperature • … tbd …
25. Thank you for your attention! 10.09.2015 25