Espresso Extraction Chart: How to Read and Use One
Master the espresso brewing control chart to dial in consistently excellent shots through measurable parameters
Quick Answer
Espresso extraction charts plot Total Dissolved Solids (TDS) against Extraction Yield percentage. The ideal espresso zone sits at 18-22% extraction yield and 8-12% TDS. Use the chart to identify under-extracted (sour) or over-extracted (bitter) shots and adjust grind, dose, or yield accordingly.
Espresso Extraction Chart: Entity Definition
Primary Entity Definition
Espresso Brewing Control Chart: A graphical tool plotting the relationship between Total Dissolved Solids (TDS—concentration) and Extraction Yield (percentage of coffee mass dissolved) to identify optimal brewing parameters and diagnose extraction problems.
Chart Components:
X-Axis (Horizontal): Extraction Yield % — Percentage of coffee grounds mass dissolved into the beverage
Y-Axis (Vertical): Total Dissolved Solids (TDS) % — Concentration of coffee solubles in the final beverage
Ideal Zone: The "Gold Cup" or optimal extraction rectangle (typically 18-22% yield, 8-12% TDS)
Understanding TDS and Extraction Yield
Total Dissolved Solids (TDS)
TDS measures the concentration of coffee solids dissolved in the espresso, expressed as a percentage. A 10% TDS means 10% of the liquid mass is coffee solids, 90% is water.
Higher TDS produces stronger, more intense flavor. Lower TDS creates weaker, more diluted taste. Espresso typically ranges from 8-12% TDS compared to 1-2% for drip coffee.
Extraction Yield
Extraction Yield measures the percentage of the original coffee grounds mass that dissolved into the beverage. An 18% extraction yield means 18% of the ground coffee's mass transferred to the cup.
This percentage represents how completely the coffee was extracted—not how strong the coffee tastes. A high yield with low TDS produces weak but over-extracted coffee.
How to Read the Extraction Chart
The espresso brewing control chart divides extraction into four quadrants based on ideal ranges. Each quadrant represents different flavor outcomes and requires different corrections.
| Quadrant | TDS | Extraction | Taste | Fix |
|---|---|---|---|---|
| Under-developed | Low (<8%) | Low (<18%) | Sour, weak, thin | Fine grind |
| Strong/Under-extracted | High (>12%) | Low (<18%) | Sour, intense, harsh | Increase yield |
| Ideal Zone | Medium (8-12%) | Ideal (18-22%) | Balanced, sweet, complex | Maintain |
| Weak/Over-extracted | Low (<8%) | High (>22%) | Bitter, weak, astringent | Coarsen grind |
| Over-developed | High (>12%) | High (>22%) | Bitter, intense, burnt | Coarsen + reduce dose |
Measuring TDS and Extraction Yield
Measuring TDS (Refractometer Method)
- 1. Calibrate refractometer with distilled water
- 2. Filter espresso sample through syringe filter to remove particles
- 3. Place drops on prism and close cover
- 4. Read TDS percentage from display or viewfinder
- 5. Record value for chart plotting
Coffee refractometers cost $300-800. For home use without refractometers, estimate based on taste and visual indicators using the simplified chart approach below.
Calculating Extraction Yield
Extraction Yield % = (Beverage Weight × TDS %) ÷ Coffee Dose × 100
Example: 18g dose, 36g beverage, 10% TDS
(36 × 0.10) ÷ 18 × 100 = 20% extraction yield
This falls within the ideal 18-22% range on the extraction chart.
Using the Chart to Dial In Espresso
The extraction chart provides a systematic approach to dialing in espresso. Start with a standard recipe (18g dose, 36g yield), taste, estimate position on the chart, and adjust variables to move toward the ideal zone.
Adjustment Strategy
Too Sour (Under-extracted): Fine the grind to increase extraction yield while maintaining the same ratio
Too Bitter (Over-extracted): Coarsen the grind to decrease extraction yield
Too Strong (High TDS): Increase yield (more output) or decrease dose
Too Weak (Low TDS): Decrease yield (less output) or increase dose
Variable Hierarchy
Adjust variables in this order for systematic dialing:
- 1. Grind Size: Primary extraction control—fine for higher yield, coarse for lower
- 2. Brew Ratio: Secondary strength control—change dose-to-yield ratio
- 3. Temperature: Fine-tuning—higher for light roasts, lower for dark
- 4. Pressure: Advanced—modify if machine allows
Chart-Free Approach: Taste-Based Dialing
Without a refractometer, use taste indicators to approximate chart position and make adjustments. This practical approach achieves excellent results through systematic tasting and adjustment.
| Taste | Chart Position | Adjustment |
|---|---|---|
| Sour, sharp, underripe fruit | Left of ideal (<18%) | Fine grind 1-2 clicks |
| Salty, thin, lacking sweetness | Lower left quadrant | Fine grind, check ratio |
| Balanced, sweet, complex | Ideal zone (18-22%) | No change needed |
| Bitter, dry, astringent | Right of ideal (>22%) | Coarsen grind 1-2 clicks |
| Burnt, harsh, smoky | Upper right quadrant | Coarsen + reduce temp |
Chart Adjustments by Roast Level
Different roast levels extract differently and may require adjustments to the ideal zone. Light roasts are harder to extract; dark roasts extract more easily.
Light Roasts
Light roasts have dense cellular structure and may require higher extraction yields (20-22%) to achieve balance. Target the right side of the ideal zone. Higher temperatures (200-205°F) help extract light roasts fully.
Medium Roasts
Medium roasts follow standard extraction chart parameters (18-22% yield). The full ideal zone produces excellent results. Adjust based on origin characteristics and processing method.
Dark Roasts
Dark roasts extract more easily and may taste best at lower extraction yields (18-20%). Target the left side of the ideal zone to avoid over-extraction bitterness from carbonized compounds.
Related Extraction Guides
Complete Dialing-In Guide
Master the systematic process of adjusting espresso parameters for optimal extraction.
Espresso Dose, Yield, and Ratio Explained
Understand the fundamental relationships that control extraction and strength.
Taste-Based Extraction Diagnosis
Identify extraction problems through taste without measurement equipment.
Refractometer for Espresso: Measuring TDS
Learn about tools for precise measurement of extraction parameters.
Under-Extracted vs Over-Extracted Espresso
Deep dive into the flavor differences and causes of extraction problems.
Espresso Shot Timing Guide
Use time as a proxy for extraction yield when measurement tools are unavailable.
Frequently Asked Questions
Do I need a refractometer to use extraction charts?
Refractometers provide precise measurements but are not required. Taste-based approximation using the chart framework works effectively for home baristas. Consider a refractometer only for advanced precision or competition preparation.
Why is 18-22% the ideal extraction range?
Research by the Coffee Brewing Center established that 18-22% of coffee mass contains the optimal balance of desirable flavor compounds. Below 18% leaves desirable flavors unextracted; above 22% extracts undesirable bitter compounds.
Can I achieve ideal extraction with any grinder?
Grinder quality affects extraction consistency significantly. Blade grinders cannot achieve consistent enough particle size for predictable extraction. Quality burr grinders are essential for reliably hitting the ideal zone.
How does brew ratio affect the chart?
Brew ratio (dose:yield) primarily affects TDS (vertical axis position). A 1:2 ratio produces higher TDS than 1:3 with the same extraction yield. Adjust ratio to move vertically on the chart; adjust grind to move horizontally.
Conclusion: Mastering Extraction Charts
The espresso extraction chart provides a framework for understanding the relationship between concentration and extraction. Use this framework to diagnose problems systematically and make targeted adjustments rather than random changes.
Start with taste evaluation to approximate chart position. Adjust grind size to move horizontally (extraction yield); adjust ratio to move vertically (TDS). Record parameters that achieve the ideal zone for consistent replication.
While precision measurement tools help, the chart framework works effectively with taste-based estimation. Understanding extraction principles transforms espresso preparation from guesswork into systematic optimization.