What’s in your coffee? Live testing at LLL’26

What do you do when you forget your reference samples for a live demo?

Grab a coffee, of course.

At London Lab Live 2026, coffee wasn’t just fuelling the conversations; it became the experiment. We tested freshly brewed coffee with the Lumero particle size analyser to showcase just how flexible the system really is.

And the results? Much more interesting than you might expect from your morning drink.

Our live demo highlighted the wide concentration range Lumero can handle, from transparent through to fully opaque samples. Even coloured, light-absorbing particles, typically a challenge for many techniques, were measured without issue. Our eye-catching display of orange/brown solutions was made using Nescafé Original Decaffeinated, diluted to a range of concentrations. Naturally, this became the perfect starting point for the first experiment.

Instant coffee. The most concentrated solution (around 10-20% of the normal concentration for drinking) was loaded straight into the Lumero and was found to have a mean particle radius of 669nm and polydispersity index of 0.18.

Fresh coffee.  Now compare that to a skinny flat white (espresso plus skimmed milk) bought from Costa coffee during the event, and things get even more interesting.

This time the equivalent peak has reduced to a mean particle radius of 402nm, , with a significantly larger polydispersity of 0.27. However, a second, much tighter peak appears at a smaller particle size – with a mean particle radius of 82 nm.

This smaller size is consistent with casein micelles, naturally occurring protein structures in milk which are the dominant remaining population after skimming, and are typically in the 25–100 nm radius range, but notoriously difficult to size due to their sensitivity to the environment. Clearly, even without knowledge of the refractive indices, the milk contributes as much to the drink as the coffee – which any coffee drinker can attest to. Suddenly, that simple coffee order becomes a neat demonstration of nanoscale biology in action.

What did Lumero reveal?

Instant coffee

Around 10–20% of the normal concentration for drinking was loaded directly into the Lumero and was found to have a mean particle radius of 669 nm and a polydispersity index of 0.18.

Nescafé Original Decaf (instant coffee)

Skinny flat white

The skinny flat white (espresso with skimmed milk) purchased from Costa Coffee during the event exhibited a mean particle radius of ~402 nm and a polydispersity index of 0.39.

Espresso plus skimmed milk
In Nescafé Original Decaf (instant coffee), a relatively uniform particle-size distribution is observed, indicating lower polydispersity than in fresh milk-based systems. In contrast, milk-based coffee exhibits a more complex, bimodal distribution, with nanoscale casein micelles contributing a distinct secondary population.

So why is this exciting?

Because this quick, improvised demo actually highlights some powerful capabilities:

  1. Nano-scale detection in complex samples
    Lumero can resolve small structures like casein micelles, even in the presence of larger, coloured particles.
  2. Broad concentration range
    From clear to opaque, even coloured, real-world solutions can be measured reliably.
  3. Ease of use
    Measurements are simple enough to be performed by non-experts, using portable equipment; no perfectly prepared samples required. There was no complex protocol development or special preprocessing required. All of these measurements were performed on the spot at what was already a very busy conference.

What we have learnt?

This live testing highlights just how much variability exists in everyday coffee, even from the same source. With rapid, on-site analysis, it’s possible to uncover hidden differences that traditional testing might miss.

Want the full story?

This demo is just a snapshot. Download the full case study to explore the complete results and insights.

Want tailored insights? Schedule a meeting today.

Picture of Dr Tiffany Wood, MPhys, PhD

Dr Tiffany Wood, MPhys, PhD

Co‑Founder & CEO, Dyneval

Dr. Tiffany Wood is an expert in soft matter with 20+ years of experience in complex fluid dynamics. As Co‑Founder of Dyneval, she specialises in translating advanced physics into real‑time diagnostic technologies for biotech, pharma, and the livestock industry.