Free Espresso Extraction Yield Calculator
Calculate exact Extraction Yield (EY%) from dry dose, liquid beverage weight, and refractometer TDS to dial in sweetness and eliminate channeling.
☕ Extraction Parameters
📊 Extraction Yield & Diagnosis
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The Specialty Coffee Extraction Yield Formula
Roasted coffee beans contain roughly 28% to 30% soluble material by weight (fats, organic acids, sugars, caffeine). The remaining 70% is insoluble cellulose plant fiber. Extraction Yield (EY%) measures the exact percentage of soluble mass extracted into your cup:
Under-Extracted (< 18% EY)
Acids and caffeine dissolve first. If you stop the shot too early, the espresso tastes sour, sharp, grassy, salty, and lacks sweetness. Fix: Grind finer or increase liquid yield.
Over-Extracted (> 22% EY)
Bitter, astringent tannins and harsh wood fibers dissolve last. Over-extracted shots taste intensely bitter, dry your tongue out like black tea, and produce an unpleasant ashy aftertaste. Fix: Grind coarser or reduce yield.
Frequently Asked Questions
What is the difference between TDS and Extraction Yield?
TDS (Total Dissolved Solids) measures the concentration or strength of the coffee in your cup (typically 8%-12% for espresso). Extraction Yield (EY%) measures how much of the ground coffee was extracted from the basket (target 18%-22%).
Can high-end precision baskets achieve 24% EY?
Yes. High-extraction precision baskets (like Wafo, Sworksdesign, and IMS Big Bang) with microscopic laser-cut holes and high flow rates can achieve 23% - 25% EY with light roast specialty coffees without astringency.
Why do I need a syringe filter for coffee refractometers?
Suspended insoluble particles (crema micro-fines) scatter light inside the refractometer prism, producing falsely inflated TDS readings. Syringe filters remove suspended solids so you measure only true dissolved compounds.