When unbroken grapes are surrounded by CO₂, they begin to absorb the CO₂ and initiate a yeast-free and oxygen-free fermentation. The resulting fermentation process is the same as what happens with conventional maceration: the yeast converts sugars into alcohol, and the anthocyanins begin to diffuse into the centres of the grape, staining the resulting juice a pinkish-red colour. A major sensory change occurs at this stage because less tannins diffuse into the flesh than do cyanins, so the juice inside the unbroken grapes will be less tannic than it would be in a conventional maceration.
Processing
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Processing Prologue
- PC 0.0 Prologue
Harvest
- PC 1.0 What's in Chapter 1?
- PC 1.01 The Harvest
- PC 1.02 Mechanical Harvesters
- PC 1.03 Ripeness
- PC 1.04 Fruit Softening
- PC 1.05 Reddening
- PC 1.06 Brix
- PC 1.07 Recap and Glossary
- PC 1.08 Comprehension Test — Chapter 1
The Wet Mill
- PC 2.00 What's in Chapter 2?
- PC 2.01 - Cleaning and Separating
- PC 2.02 Sorting
- PC 2.03 Flotation
- PC 2.04 - Pulping
- PC 2.05 Drum Pulpers
- PC 2.06 Disk Pulpers
- PC 2.07 Screen Pulpers
- PC 2.08 Interview with Ryan Brown
- PC 2.09 Recap and Glossary
- PC 2.10 Comprehension Test — Chapter 2
Flora
- PC 3.0 What's in Chapter 3?
- PC 3.01 The Fermentation Tank
- PC 3.02 The Fermentation Process
- PC 3.03 Temperature and Time
- PC 3.04 Bacteria, Fungi, or Yeast?
- PC 3.05 Filamentous Fungi
- PC 3.06 Respiration and Fermentation
- PC 3.07 Washing
- PC 3.08 Wastewater Management
- PC 3.09 - Wastewater Treatment
- PC 3.10 Recap and Glossary
- PC 3.11 Comprehension Test — Chapter 3
Controlled Fermentation
- PC 4.0 What's in Chapter 4?
- PC 4.01 Semi-Carbonic Maceration in Winemaking
- PC 4.02 An Interview with Hugo Silva
- PC 4.03 Carbonic Maceration
- PC 4.04 An Interview with Jamison Savage
- PC 4.05 Bag Fermentation — An interview with Nikolai Fürst
- PC 4.06 Innoculation
- PC 4.07 Kenyan Double Fermentation
- PC 4.08 Fermentation in Kenya — An Interview with Mette-Marie Hansen
- PC 4.09 Hot Fermentation — Interview with Petra Střelecká
- PC 4.10 Lactic Processing
- PC 4.11 Interview with Felipe Sardi, La Palma y El Tucan
- PC 4.12 Recap and Glossary
- PC 4.13 Comprehension Test — Chapter 4
Dry Processing
- PC 5.00 What’s in Chapter 5?
- PC 5.01 Naturals
- PC 5.02 Interview with Anabella Meneses
- PC 5.03 Quality Controls
- PC 5.04 Sugars in Natural Processing
- PC 5.05 Fermentation in Natural Processing
- PC 5.06 Mechanical Demucilagers
- PC 5.07 Flavour vs. Efficiency
- PC 5.08 Pulped Naturals and Honey Processing
- PC 5.09 The Short History of Honey Processing — With Francisco Mena
- PC 5.10 Recap and Glossary
- PC 5.11 Comprehension Test — Chapter 5
Drying
- PC 6.00 What's in Chapter 6?
- PC 6.01 Drying Patios
- PC 6.02 Raised Beds
- PC 6.03 Guardiolas — Mechanical Coffee Dryers
- PC 6.04 Taints Caused by Improper Drying
- PC 6.05 Interview with Rachel Peterson
- PC 6.06 Measuring the Moisture Content of Parchment Coffee
- PC 6.07 Water Activity in Green Coffee
- PC 6.08 Ochratoxin
- PC 6.09 Recap and Glossary
- PC 6.10 Comprehension Test — Chapter 6
Dry Milling
- PC 7.00 What's in Chapter 7?
- PC 7.01 Silos and Bodegas
- PC 7.02 An Interview with Marta Dalton
- PC 7.03 Hulling
- PC 7.04 Screening — Size-Grading Green Coffee
- PC 7.05 Density Sorting
- PC 7.06 Bagging, Super Sacks, and Shipping Containers
- PC 7.07 An Interview with Diego Lara of GrainPro
- PC 7.08 Recap and Glossary
- PC 7.09 Comprehension Test — Chapter 7
Processing Final Assessment
- PC 8.01 A Final Word
- PC 8.02 Final Assessment