If you’ve ever come across coffee forums or brewing guides, you’ve probably seen the term “TDS” thrown around. But what does it actually mean? And does it matter to home brewers?
TDS stands for Total Dissolved Solids. In simple terms, it refers to the amount of coffee stuff that’s actually dissolved in your cup. Understanding TDS can help you brew better, more balanced coffee — even if you don’t own a refractometer.
What Is TDS in Coffee?
TDS stands for Total Dissolved Solids, measured as a percentage. It tells you how much of the coffee has dissolved into the water during brewing.
- A TDS of 1.25% means 1.25% of your drink is coffee solids, and the rest is water.
- The rest of the cup (∼98.75%) is water carrying flavour, oils, and compounds.
Why It Matters:
- High TDS = stronger, more concentrated brew
- Low TDS = weaker, more diluted coffee
What’s the Ideal TDS for Coffee?
There’s no universal “perfect” TDS, but generally:
| Brew Method | TDS Range (%) |
|---|---|
| Espresso | 8.0 – 12.0 |
| Moka Pot | 3.0 – 4.5 |
| Aeropress | 1.2 – 1.5 |
| Pour-over/V60 | 1.2 – 1.4 |
| French Press | 1.3 – 1.6 |
| Cold Brew | 1.5 – 2.0 |
Want clarity in your brew? Learn about Grind Size and Brew Time
TDS vs Strength: Are They the Same?
Not quite.
- TDS is a scientific measurement.
- Strength is how strong your coffee tastes.
Example: A dark roast Moka pot may have high TDS but feel less acidic or sharp than a light roast V60 with lower TDS but higher brightness.
TDS helps you understand strength, but extraction and flavour still play major roles.
How TDS and Extraction Work Together
TDS alone doesn’t define a great cup — extraction does.
- Under-extracted coffee: Low TDS, sour or watery taste
- Over-extracted coffee: High TDS, bitter or hollow taste
- Well-extracted: Balanced sweetness, clarity, and body
The goal? Balanced extraction with a TDS that suits your method and taste.
How to Measure TDS (and Should You?)
With a Refractometer:
- Digital devices measure %TDS from a coffee sample
- Great for professionals or deep hobbyists
Without Equipment:
- Use taste and recipe consistency
- Adjust variables: grind size, brew time, water-to-coffee ratio
Tip: If your brew feels too weak or too strong, you’re already sensing TDS changes without needing tools.
How to Adjust TDS at Home
- Change brew ratio (coffee:water)
- More coffee = higher TDS
- Less coffee = lower TDS
- Grind size
- Finer grinds increase extraction
- Coarser grinds reduce TDS
- Brew time
- Longer = more dissolved solids
- Shorter = less
Internal Link: Struggling with weak brews? Try our Fixes for Watery Coffee
What TDS Can Teach You
- Helps you standardise recipes
- Understand why your espresso tastes different from your French press
- Fine-tune your brews for consistency
Even without measuring, the concept of TDS can improve how you troubleshoot and experiment.
Final Thoughts
TDS is one of those geeky coffee terms that actually has real-world relevance. By understanding how your brew strength relates to grind size, ratio, and time, you can consistently make better coffee without any gadgets.
Whether you want rich espresso or delicate pour-over, keeping an eye (and palate) on TDS will level up your brews.
