Coffee Extraction Chart: How to Read It and Dial In Better Coffee

The coffee extraction chart — formally known as the Brewing Control Chart — plots beverage strength, expressed as total dissolved solids (TDS), against extraction yield (EY), with brew ratio relating the two variables. It was first published by E.E. Lockhart in 1957 and versions of it still hang in roasteries and cafés worldwide. The classic reference window sits at roughly 1.15–1.35% TDS and 18–22% extraction yield — a historical guideline for filter and drip coffee, not a universal definition of correctly brewed coffee, and modern preference research has complicated it considerably.

Because the chart relies on two related but separate measurements, it is worth being precise about the terms first:

	TDS (Total Dissolved Solids)	Extraction Yield (EY)	Brew Ratio
What it measures	Concentration of dissolved coffee material in the finished beverage	Proportion of the dry grounds' mass that ended up dissolved in the liquid	Water relative to coffee (e.g., 1:15)
Classic filter reference	≈ 1.15–1.35%	≈ 18–22%	≈ 1:14 to 1:18
What it tells you	How strong the cup tastes	How much of the coffee's soluble material left the grounds	Relates the two: strength ≈ extraction yield ÷ brew ratio

What Does a Coffee Extraction Chart Actually Show?

A coffee extraction chart shows where a brewed cup lands on two separate measurements. TDS is the concentration of dissolved coffee material in the finished beverage, expressed as a percentage. Extraction yield is the percentage of the dry coffee grounds' original mass that ended up dissolved in the liquid.

The two are mathematically linked through brew ratio, so the chart can be read in any direction once the ratio is known. The classic layout uses brew-ratio diagonals, a central box marking the historical "ideal" zone, and surrounding regions describing weaker or stronger coffee at lower or higher extraction levels.

The chart traces to 1950s research by E.E. Lockhart, which proposed that cup quality relates to how much coffee material dissolves into the liquid. The key thing to understand about the tool itself: a chart is a diagnostic map, not a recipe. It tells you where a brew landed, not what to change next.

What Are the Classic TDS and Extraction Yield Ranges?

The original 1957 figures placed "ideal" filter coffee at 1.15–1.35% TDS and 18–22% extraction, as Barista Hustle documents in its historical discussion of the chart. That window became the industry's Gold Cup standard for decades. It describes filter and drip coffee specifically — a historical industry guideline, not a universal law of good coffee.

Specialty coffee has trended toward higher extractions in recent years, and a 2013 Specialty Coffee Association study found a slight consumer preference for extractions toward 20–24%. Barista Hustle's 2018 survey of Advanced Coffee Making readers set out to re-examine the long-standing 18–22% window and gather common brew ratios worldwide, including for less-studied methods such as Ibrik (Cezve) and the moka pot. A 2023 peer-reviewed study in the Journal of Food Science presented a new Brewing Control Chart relating sensory properties and consumer liking to brew strength, extraction yield, and brew ratio, and found two distinct consumer preference clusters — no single "correct" target applies to all drinkers.

The practical takeaway: published ranges are starting reference points for a given brewing context, not objective pass/fail thresholds.

TDS vs. Extraction Yield: What's the Difference?

TDS and extraction yield measure different things, and keeping them separate is the single most important step in reading the chart correctly. TDS is concentration: how much dissolved coffee material is present in the finished beverage — how strong the cup tastes. Extraction yield is a proportion of the dry coffee: how much of the grounds' original mass was transferred into the beverage. A small, strong espresso and a large, weak batch brew can share the same extraction yield at very different TDS values.

Because strength, extraction, and brew ratio are linked, you can change strength without changing extraction by changing how much water you use. A high TDS number does not mean over-extracted, and a low TDS number does not mean under-extracted — strength and extraction are separate measurements, and neither implies the other.

Both are measured with a refractometer, a scale, and a brew-ratio calculation. Measurement error is real at these small percentages: small weighing mistakes propagate, so consistent technique matters more than decimal-level precision.

How Grind Size, Time, Temperature, Flow, and Agitation Affect Extraction

Grind size is often described as an "extraction speed" dial, but that shorthand oversimplifies things. Finer particles expose more surface area to water, which can increase extraction — but in percolation brewing an excessively fine grind also changes the permeability of the coffee bed: flow slows, fines can clog the filter, water can channel or bypass parts of the bed, and contact time shifts. Any of these can leave extraction lower, or less even, than the finer grind was meant to achieve.

Contact time matters, but it does not determine extraction on its own. A coarse grind brewed long can still under-extract, and a fine grind brewed briefly can still over-extract. Time is one variable in a system, not the measure of the result.

Water temperature is a rate variable: hotter water extracts faster, and the commonly cited brewing range sits well below boiling for most methods. Agitation and flow rate also matter — stirring, pouring technique, and how water moves through the bed affect local concentration gradients and the evenness of extraction.

These variables interlock. Changing one shifts the others, so adjust one at a time when dialing in, and give each change a fair trial before moving to the next.

Why Does My Coffee Draw Down Too Fast or Too Slow?

The first correction to make about brewing speed: drawdown or brew time is not the same thing as extraction yield. A fast drawdown does not prove a coffee is under-extracted, and a slow drawdown does not prove it is over-extracted. Flow time, beverage strength, extraction yield, and the sensory result are four different things, and a coffee can move each independently of another.

What influences flow? Grind size, dose and bed depth, filter characteristics, fines, pouring pattern, agitation, channeling, brewer geometry, and the coffee itself (roast, freshness, density). A fast drawdown with an intact, evenly extracted bed is a different situation from a fast drawdown caused by a channel that bypassed half the grounds — and they can taste nothing alike.

When measurements show extraction genuinely is too low, grinding finer, extending contact time, or raising temperature tends to increase it; the inverse lowers it. Resist treating any single instruction — including "reduce agitation" — as universal. Agitation influences extraction and bed behavior differently depending on the brewing system, so treat it as a variable to experiment with in your setup, not a preset lever.

How to Diagnose Coffee Using Taste and Measurements Together

"Sour means under-extracted" and "bitter means over-extracted" are troubleshooting heuristics, not universal scientific rules. They are worth checking first, but roast level, water chemistry, coffee age, and individual perception all interfere with that shortcut — a sour or bitter cup with perfectly normal extraction numbers is common.

The strongest current evidence comes from a 2023 peer-reviewed study by Guinard and colleagues at the UC Davis Coffee Center, published in the Journal of Food Science: it found sensory and preference relationships considerably more complicated than the classic chart implies, and identified two distinct consumer preference clusters with different likes and dislikes across the chart. One important limitation: the consumer-preference results were based primarily on young adult consumers in Northern California and should not be read as universal global preferences.

Combine taste with numbers: measure TDS, calculate EY from the brew ratio, and locate the brew on the chart before deciding what to change — the troubleshooting table below pairs observations with the measurements that confirm or rule out the usual suspects.

For readers who want a deeper, book-length treatment of extraction and brewing science, The Complete World of Coffee: The History, Craft, and Science of Specialty Coffee covers these relationships in detail.

Coffee Extraction Troubleshooting Chart

Use this table as a starting point for investigation, not a verdict. Taste tells you what to measure; the measurements tell you what to change.

Observation	Measurements to check	Possible causes	Useful next experiment
Sour, sharp, or salty	TDS, calculated EY, brew temperature, grind setting, drawdown pattern	Genuinely low EY — but also fast drawdown with channeling, very light roast, cool water, coarse grind, uneven extraction, or acidity inherent to the coffee	Measure EY. If low, grind a step finer or extend contact time. If normal, look at roast, water chemistry, and the coffee itself before changing the brew.
Bitter, dry, or astringent	TDS, calculated EY, drawdown pattern, grind distribution	Genuinely high EY — but also dark roast, channeling, high temperature, fines in the cup, or coffee characteristics	Measure EY. If high, grind coarser or shorten contact time. If normal, check roast level, channeling, temperature, and water.
Weak, hollow, or thin	TDS first, then calculated EY	Low strength from too much water for the dose — or low extraction yield — or both. Different problems, different fixes.	If TDS is low but EY is normal, use less water or more coffee. If both are low, grind finer or extend contact time.
Muddy, heavy, or dull	TDS, calculated EY, drawdown pattern	High TDS from a tight ratio, uneven flow, or high extraction	Loosen the brew ratio slightly or improve pour evenness, then re-measure before further changes.
Drawdown much faster than usual	Drawdown time, TDS, calculated EY	Coarse grind, low dose, channeling or bypass, or a filter/bed issue — not necessarily under-extraction	Check whether EY actually dropped. If it did, grind finer or address channeling. If not, the fast flow alone is not a defect.
Drawdown much slower than usual	Drawdown time, TDS, calculated EY	Fine grind or many fines, deep bed, or a clogged/slow filter — not necessarily over-extraction	Check whether EY actually rose. Grind coarser only if EY or flavor indicates it; otherwise treat it as a flow issue.

How Different Brewing Methods Fit the Extraction Chart

Coffee extraction methods group by mechanism: immersion (French press, cupping), percolation or pour-over (V60, Chemex, drip), and pressure (espresso, moka pot). The same chart logic applies across methods — strength and extraction are always separate measurements — but target zones and typical ratios shift with the brewing context.

Espresso occupies a very different region of the chart: its TDS sits several times above the filter range even when extraction yields overlap. The classic 1.15–1.35% TDS range refers to filter and drip coffee, and must not be applied to espresso or other concentrated methods.

Published guidance is thinner for some methods: Barista Hustle's 2018 survey specifically sought common brew ratios for the under-studied Ibrik (Cezve) and moka pot, and the 2023 Journal of Food Science study focused on drip-brewed coffee.

How to Measure Coffee Extraction at Home

Measuring coffee extraction at home takes a scale accurate to 0.1 g, a refractometer, and a consistent brewing routine: measure the coffee dose and the beverage mass, read the TDS, then derive extraction yield from those numbers.

One caution: extraction yield calculations depend on the brewing method and measurement approach. In immersion brewing, some water is retained in or adsorbed to the grounds; percolation is treated differently, and espresso has its own conventions. A dedicated coffee extraction calculator or spreadsheet handles the arithmetic — small errors in dose or beverage weight propagate into the EY figure.

Record dose, beverage yield, brew time, grind setting, water temperature, TDS, and calculated EY so results are repeatable. After a few sessions you will see your own patterns — which is the point of the chart.

Key Takeaways

• The coffee extraction chart plots beverage strength (TDS) against extraction yield (EY), with brew ratio relating the two.
• The original chart was published by E.E. Lockhart in 1957: 1.15–1.35% TDS and 18–22% extraction for filter/drip coffee — a guideline, not a universal rule.
• EY and TDS measure different things: EY is the fraction of coffee solids dissolved out of the grounds; TDS is their concentration in the cup.
• Brew time or drawdown alone does not determine extraction; grind size, temperature, agitation, flow, bed depth, and fines all interact.
• A 2023 peer-reviewed update found more complicated sensory and preference relationships than the classic chart implies, including two consumer preference clusters.
• Sour does not reliably mean under-extracted and bitter does not reliably mean over-extracted; combine taste with measurement.
• Espresso operates in a very different strength region than filter methods; filter-based TDS targets do not transfer.

References

1. Guinard, J.-X., Frost, S., Batali, M., Cotter, A., Lim, L. X., & Ristenpart, W. D. (2023). A new Coffee Brewing Control Chart relating sensory properties and consumer liking to brew strength, extraction yield, and brew ratio. Journal of Food Science, 88(5), 2168–2177. DOI: 10.1111/1750-3841.16531.
2. Barista Hustle. (2021). Towards a Common Coffee Control Chart. Published October 2, 2021.
3. Lockhart, E. E. (1957). The Soluble Solids in Beverage Coffee as an Index to Cup Quality. Food Technology.