Sugars & Carbohydrates¶
Sugars & Carbohydrates in Coffee Major component of green coffee (50-60% dry weight). Essential for Maillard reactions and caramelization. Broken down during roasting. Source of sweetness and body. Critical for flavor development. Understanding chemistry improves roasting and appreciation. Carbohydrate Types Simple Sugars (Monosaccharides) Glucose, fructose, arabinose. Small amounts in green coffee. Increase slightly during roasting initially. Rapidly consumed in reactions. Maillard reaction substrates. Sweet taste contributors (low levels). Disaccharides Sucrose: Major sugar in green coffee (6-9% Arabica, 3-7% Robusta). Breaks down during roasting. Creates sweetness before decomposing. Maillard and caramelization substrate. Critical for roasting reactions. Polysaccharides Cellulose: Structural (30-40% green coffee). Cannot be extracted or tasted. Provides bean structure. Arabinogalactan: Soluble fiber (15-20%). Extracts into brew. Contributes to body/viscosity. Mannan: Soluble polysaccharide. Body contributor. Sucrose in Coffee Content Variation Arabica: 6-9% sucrose (higher than Robusta). Robusta: 3-7% sucrose (lower than Arabica). High altitude: Higher sucrose (slow maturation). Contributes to Arabica quality advantage. Sweetness potential indicator. Function in Roasting Substrate for Maillard reactions. Substrate for caramelization. Decomposes starting ~160°C. Almost completely gone by dark roast. Creates hundreds of flavor compounds. Brown color development. Sweetness in light/medium roasts. Sweetness Source Sucrose provides direct sweetness. Some survives light roasting (residual). Medium roast: Mostly consumed but caramelized products sweet. Dark roast: Sucrose destroyed, bitterness dominates. Roast level critically affects sweetness. Caramelization Process Sugar pyrolysis without amino acids. Occurs above 160°C (accelerates 170-200°C). Creates caramel flavor compounds. Brown color (caramels). Distinct from Maillard (involves amino acids). Both occur during roasting. Temperature Ranges 160-170°C: Caramelization begins. 170-190°C: Rapid caramelization. 190-200°C: Extensive breakdown. Above 200°C: Carbonization begins (burnt). Time and temperature both matter. Flavor Development Toffee, caramel, butterscotch notes. Brown sugar, molasses. Sweetness perception. Pleasant complexity. Balances acidity. Medium roast showcases. Over-caramelization: Bitter, burnt. Color Contribution Caramel polymers create brown color. Darker roasts more caramelization. But also more carbonization (black). Balance creates target color. Visual roast level indication. Maillard & Sugar Sugar as Substrate Reducing sugars (glucose, fructose, etc.) react with amino acids. Sucrose breaks down into reducing sugars first (hydrolysis). Then Maillard reactions proceed. Non-reducing sugars cannot directly participate. Breakdown step essential. Maillard Reactions Sugar + amino acid → hundreds of compounds. Creates roasted, nutty, chocolate flavors. Brown color (melanoidins). Most important roasting reactions. Covered in Maillard Reaction & Caramelization section. Sugar Destruction Consumed in Maillard reactions. Caramelized and broken down. Almost no sugar remains in dark roast. Light roast retains some. Medium roast transitional. Dark roast bitter partly from sugar destruction. Polysaccharides & Body Soluble Polysaccharides Extract into brewed coffee. Contribute to viscosity. Creates body/mouthfeel. Arabinogalactans primary. Mannans secondary. Not sweet but textural. Extraction Variables Temperature: Higher extracts more. Time: Longer extracts more. Grind: Finer releases more. Method: Immersion extracts more than percolation. Body variation across methods partly polysaccharide-based. Body Sensation Thick, syrupy, viscous mouthfeel. From polysaccharides + oils + suspended solids. Coffee "body" combination. Polysaccharides significant contributor. High-quality Arabica often good body (polysaccharide content). Roasting & Carbohydrates Drying Phase Minimal carbohydrate change. Moisture loss primary. Structure preparation. 160°C threshold approaching. Browning Phase Maillard reactions begin. Caramelization begins. Sucrose breakdown accelerates. Color develops. 160-196°C range. Major chemical activity. Development Phase Extensive Maillard and caramelization. Sugar consumption continues. First crack from pressure (partly CO2 from reactions). 196°C onward. Rapid chemical changes. Sweetness peak then decline. Dark Roast Sugars nearly depleted. Caramelization extreme. Carbonization begins. Bitter compounds dominate. Sweetness lost. Roast character overwhelms origin. Sugar chemistry exhausted. Sugar & Quality High Altitude = More Sugar Cool temperatures slow maturation. Extended ripening allows sugar development. Denser beans result. Higher quality potential. Sweetness and complexity. Altitude-quality correlation partly sugar-based. Variety Differences Bourbon varieties sweeter than others. Genetic variation in sugar content. Some hybrids lower sugar. Sweetness reputation (Bourbon, Geisha). Selection and breeding consider sugar. Processing Impact Natural process: Fruit sugars absorbed somewhat (controversial extent). Honey process: Mucilage sugar absorption possible. Washed process: No external sugar influence. Processing affects perceived sweetness but green bean sugar content fixed. Freshness & Sugar Sugar content stable in green coffee (years). Roasted coffee sugars already transformed. Stale coffee no less sugar but oxidized aromatics. "Sweetness" in cup from aromatic compounds more than actual sugar. Chemistry vs. perception distinction. Sugar Measurement Refractometer Measures dissolved solids (TDS). Cannot distinguish sugar from other solubles. Total dissolved solids metric. Not sugar-specific. Chemical Analysis HPLC (High-Performance Liquid Chromatography). Quantifies individual sugars. Research and quality analysis. Lab equipment. Precise measurement. Not practical for routine use. Tasting Assessment Subjective sweetness evaluation. Cupping scores sweetness (10 points). Sensory analysis primary. Trained palates reliable. Practical method for roasters. Sweetness in Brewing Extraction Impact Under-extraction: Lack of sweetness (insufficient extraction of sweet compounds). Optimal extraction (18-22%): Balanced sweetness. Over-extraction: Bitterness overwhelms sweetness. Sweet spot narrow. Extraction precision matters. Brewing Variables Temperature: Lower temps can emphasize sweetness (less bitter). Ratio: Lower ratios (stronger) can seem sweeter (concentration). Water: Good water allows sweetness to express. Grind: Proper grind extracts balanced sweetness. Sweetness Perception Affected by acidity (contrast). Affected by bitterness (masking). Affected by aroma (sweetness suggestion). Body influences sweetness perception. Multi-sensory integration. Not just sugar content.
End of Coffee Terminology Update - 75 Topics Total
Related Notes: - Coffee Terminology MoC