Barista Terminology | Episode 6: Grind & Extraction Variables
We are proud to continue our educational series on QahwaWorld.com, designed to equip baristas and coffee enthusiasts with essential industry knowledge. Titled “Barista Terminology,” this comprehensive series delivers clear, concise insights into the foundational concepts shaping the world of coffee. Spanning more than 20 episodes, each installment explores a distinct element of coffee preparation and culture.
In Episode 6, we delve into one of the most critical aspects of brewing: the relationship between grind size, extraction variables, and brew quality. From grind consistency and water temperature to brew ratios and TDS, this episode defines the technical terms every barista must understand to master the art of extraction. Whether you’re fine-tuning an espresso shot or crafting a pour-over, this guide will help you unlock the full flavor potential of your beans through precision and control.
The perfect cup of coffee is not just about quality beans and good equipment — it’s about precision. Grind size, brewing time, and water contact all play vital roles in how flavors are extracted. In this episode, we define the essential variables that every barista must understand and control to achieve optimal extraction.
1. Grind Size
Refers to how fine or coarse the coffee is ground. Different brewing methods require different grind sizes. For example, espresso needs a fine grind, while cold brew requires a coarse one.
2. Grind Consistency
How uniform the particles are after grinding. Inconsistent grind leads to uneven extraction — some particles over-extract (bitter), others under-extract (sour).
3. Extraction
The process of dissolving soluble compounds from coffee into water. Proper extraction balances acidity, sweetness, and bitterness.
4. Under-Extraction
When too little is extracted from the coffee. Results in sour, acidic, or salty flavors. Common causes include too coarse a grind or too short brew time.
5. Over-Extraction
When too much is extracted. Leads to bitterness, dryness, and harsh flavors. Usually caused by too fine a grind or long brew time.
6. Brew Time
The total time water is in contact with coffee. Each brewing method has an ideal time range. Too fast = under-extraction. Too slow = over-extraction.
7. Brew Ratio
The proportion between the amount of coffee and water used. A common espresso ratio is 1:2. Adjusting this changes strength and flavor.
8. Dose
The amount of dry ground coffee used in a recipe, typically measured in grams. Key to consistency in taste and strength.
9. Yield
The amount of brewed coffee produced (in grams or milliliters). In espresso, it’s the liquid that ends up in the cup after extraction.
10. TDS (Total Dissolved Solids)
The measurement of how much soluble material has been extracted into the brew. Used to evaluate strength and extraction percentage.
11. Extraction Yield
A percentage that shows how much of the coffee’s soluble material was extracted. Ideal yield ranges between 18%–22% for most brews.
12. Distribution
The even spread of ground coffee in the filter basket before tamping. Prevents channeling and promotes uniform extraction.
13. Channeling
Occurs when water flows unevenly through the coffee bed, creating weak spots. Leads to both under- and over-extraction in the same shot.
14. Blooming
The initial stage of brewing (especially in pour-over), where hot water activates gases in fresh coffee, causing it to expand and release carbon dioxide. Improves flavor clarity.
15. Water Temperature
Ideal brewing temperature ranges from 90°C to 96°C. Too cool = under-extraction. Too hot = bitterness and over-extraction.
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