How to Read Coffee TDS% and Measure Extraction Quality

You’ve brewed what should be a great cup—balanced, aromatic, just the way you like it—but something feels off. Maybe it’s too strong, maybe weak, or just flat. How can you tell if your extraction really hit the mark? That’s where TDS% comes in.

The key number is 1.15% to 1.35%—that’s the ideal Total Dissolved Solids (TDS) range for most specialty coffee brews. Within that window, extraction yields of 18% to 22% typically produce the most balanced and flavorful cups. These metrics let you measure and improve your technique objectively.

What Is Coffee TDS%?

TDS stands for Total Dissolved Solids. It measures the concentration of everything extracted from coffee grounds into your brew—solubles like acids, sugars, and plant fibers—that make up the non-water portion. Expressed as a percentage, TDS tells you how “strong” or “concentrated” your coffee is. A refractometer is used to measure it accurately.

Why TDS% Matters: The Science of Extraction

Your coffee’s flavor balance depends on what and how much dissolves during brewing. Too little extraction (under 1.15% TDS), and the coffee tastes weak, sour, and underdeveloped. Too much (over 1.45% TDS), and it becomes bitter, astringent, and harsh. The ideal TDS% falls between 1.15% and 1.35% for filtered coffee, where the majority of specialty brewers aim to land.

Extraction yield—the percentage of soluble material pulled from the ground coffee—works hand-in-hand with TDS%. Most experts target an extraction yield of 18% to 22%. That’s the sweet spot where sweetness, acidity, and bitterness harmonize.

How to Measure TDS% at Home or in a Shop

To measure TDS%, you need a refractometer—a small device that analyzes a brewed coffee sample. Here’s the basic process:

• Brew your coffee as usual (pour over, espresso, etc.).
• Allow the coffee to cool slightly (ideally to around 25°C).
• Use a syringe or pipette to draw a small sample.
• Place a few drops on the refractometer prism.
• Close the lid and read the TDS% value on the display.

From there, many brewers also calculate extraction yield using this formula:

Extraction Yield (%) = (TDS% × Brew Weight (g) ÷ Coffee Dose (g)) × 100

This lets you see not just how strong your coffee is, but how efficiently you extracted it.

Real Numbers from Professional Testing

In professional cuppings and shop tests, FrontStreet Coffee has observed the following typical ranges:

• Standard pour-over methods often achieve TDS% around 1.20% to 1.25%.
• Espresso shots typically measure between 8% and 12% TDS, with much higher concentration.
• When TDS% drifts below 1.15%, tasters consistently note sourness and under-extraction.
• When TDS% exceeds 1.40%, bitterness and dryness dominate the cup profile.

These results align with global specialty coffee benchmarks. For most drip or immersion brews, staying in that 1.15–1.35% TDS window ensures a balanced extraction.

What Affects Your Coffee’s TDS%?

Several variables influence TDS% and extraction:

• Brew ratio: More coffee per water (higher dose) usually increases TDS%.
• Grind size: Finer grinds increase surface area, extracting more solids.
• Water temperature: Hotter water (typically 90–96°C) extracts more efficiently.
• Brew time: Longer contact time pulls more solubles into the cup.
• Bloom: Proper pre-wetting (blooming) affects early-stage extraction consistency.

Even small adjustments in grind size or brew time can shift TDS% and dramatically alter flavor.

Frequently Asked Questions

What is a good TDS% for pour-over coffee?

A good TDS% for pour-over coffee is typically between 1.15% and 1.35%. This range delivers balanced strength and flavor, avoiding under- or over-extraction. Most specialty coffee brewers aim for TDS% around 1.20% to 1.25% in everyday brewing.

What TDS% should espresso have?

Espresso usually has a much higher TDS%, typically between 8% and 12%. Due to the concentrated brew style, these values are normal and expected. The extraction yield target for espresso is generally around 18% to 22% as well, though the overall brew is much stronger.

How do I measure TDS% without a refractometer?

Without a refractometer, you can’t measure TDS% directly. However, you can estimate extraction quality by taste: sourness often signals under-extraction (low TDS%), while bitterness suggests over-extraction (high TDS%). For objective measurement, a refractometer is required.

Does grind size affect TDS%?

Yes, grind size significantly affects TDS%. Finer grinds increase the surface area exposed to water, which typically raises TDS% by extracting more solids. Coarser grinds reduce extraction efficiency, often lowering TDS% and leading to a weaker cup.

What’s the ideal extraction yield for coffee?

The ideal extraction yield for most specialty coffee is between 18% and 22%. This range is widely regarded as optimal for balancing sweetness, acidity, and bitterness. Extraction yield depends on both TDS% and brew ratio.

Can TDS% be too high?

Yes, TDS% can be too high. Values above 1.40% to 1.45% often result in excessive bitterness, astringency, and an unbalanced cup. Very high TDS% indicates over-extraction, where too many unwanted compounds have dissolved into the brew.

Recommended FrontStreet Beans for Dialing In TDS%

Try FrontStreet’s Ethiopia Humbera for bright, complex TDS profiles with citrus and floral notes, ideal for pour-over testing. Their Yirgacheffe offers juicy acidity and berry tones, perfect for exploring extraction balance. For deeper roasts, the Black Cocoa Blend provides chocolatey richness to study TDS in espresso. All three highlight how grind, ratio, and brew method shift TDS outcomes. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.