Can the Taste of Coffee Be Influenced by the Surface We Touch?

Changing the taste of coffee may not always require altering the beans, roast, or recipe.

A new study by Natsumi Kubo and Atsunori Ariga from Chuo University shows that the surface texture we perceive with our hands while drinking coffee can affect the taste evaluation of the beverage under certain conditions. The study was published online on June 3, 2026, in Multisensory Research.

The most striking result of the research is that the effect is not limited to the cup itself.

Participants who touched a smooth surface simultaneously rated the same coffee as less acidic under certain conditions. Moreover, a similar effect was observed even when the touched object was completely independent of the cup. According to the researchers, the simultaneous occurrence of tactile and taste stimuli is important; the effect disappeared when the touch and the moment of drinking coffee were separated.

This finding raises a broader question for café businesses: Is the coffee experience created solely by the coffee itself, or are the table, sleeve, menu, and even the phone that the customer touches simultaneously also part of the perception?

In the first experiment, 92 people participated in a blind tasting

The first experiment involved 92 Japanese participants in Tokyo.

Participants were blindfolded and asked to drink the same black coffee from cups with different outer surfaces. The coffee used in the study is described as Nestlé “Rich Blend” capsules; approximately 115 milliliters of coffee was served at around 68°C. The cups themselves were selected from the same material; the difference was created by the outer sleeve surface.

One sleeve had a rough, sandpaper-like surface. The other was smoother kraft paper.

Participants who first tried the rough sleeve and then drank coffee from the smooth sleeve rated the coffee from the smooth surface as less acidic. However, when the order was reversed, the same effect was not observed.

This detail is extremely important.

The result of the research is not that "a smooth surface always makes coffee feel less acidic." The effect appears to depend on the order of the experiment and the context.

No reliable change was confirmed in sweetness and aftertaste in the same study.

The second experiment used an object completely independent of the cup

In the second experiment, the researchers asked a more interesting question:

Is it really necessary for the touched surface to be on the cup?

This time, 24 participants touched a separate smooth or rough object with their other hand while drinking coffee. The tactile stimulus was not physically connected to the cup of the beverage.

Nevertheless, the effect between touch and taste re-emerged.

The researchers define this result as "sensation transference." Simplified, it means that perceptual information from one sense is transferred to the evaluation of another sense.

This has a striking implication for cafés.

The customer is not only holding the cup while drinking coffee. They are touching the table, holding the menu, using their phone, or carrying a tray. The tactile properties of these could theoretically also be part of the beverage perception.

Chuo University also emphasizes in the practical interpretation of the research that objects frequently touched while drinking coffee, such as tables, menus, and smartphones, should be given special attention.

But touch and drinking must occur simultaneously

The third experiment investigated the limits of this effect.

In the experiment involving 48 participants, when the moments of touch and drinking coffee were separated, the effect disappeared.

The phrase "contextually tolerant but temporally intolerant" in the title of the research comes from here.

This means that the effect is relatively tolerant to context: the touched object does not have to be the cup.

However, it is not tolerant to time: the tactile stimulus and the taste experience must occur simultaneously.

This result is significant for café design because not only the surfaces that the customer sees or has touched when entering the space, but also the surfaces they touch while drinking coffee become important.

This is not a new area of research

The new study has not emerged in isolation.

A study by Fabiana Carvalho, Valentina Moksunova, and Charles Spence published in Food Quality and Preference in 2020 showed that the cup surface texture could affect taste evaluations in 231 expert and amateur participants drinking specialty coffee.

In the study, Q Graders rated coffee drunk from a rough cup as more acidic, while amateur consumers found coffee from a smooth cup to be sweeter. Both groups rated the aftertaste of coffee drunk from a rough cup as drier.

In another study, different cup sleeve materials were associated with taste characteristics. A cardboard surface was more strongly associated with bitterness, while a towel-like surface was associated with sweetness; black coffee was perceived as less bitter when consumed with a towel sleeve compared to a cardboard sleeve.

Therefore, the research literature does not arrive at a single "ideal coffee cup" conclusion. Rather, it supports a common point:

The tactile properties outside the serving vessel are also part of coffee perception.

Cup selection is no longer just an aesthetic decision

In cafés, cup selection is generally made based on four criteria:

price, durability, heat retention, and brand aesthetics.

New research adds a fifth criterion: sensory harmony.

For example, a shiny, very smooth porcelain surface does not guarantee that a rustic, textured ceramic will be evaluated the same way by the consumer for the same coffee.

However, one should not conclude from this that "if we put high-acidity coffee in a smooth cup, the problem will be solved."

The effect in the new study was small, condition-dependent, and only appeared in certain evaluations. It was also tested in a laboratory-like controlled environment.

Therefore, cup texture is not a tool to compensate for recipe errors, poor extraction, or incorrect roasting.

It may be more interesting for specialty coffee

The topic is particularly meaningful for specialty coffee businesses.

These businesses try to control numerous parameters such as bean origin, process, roast profile, water recipe, grind, and serving temperature.

However, the ultimate experience perceived by the customer is completed in the cup after all these technical variables.

A service aiming to highlight the distinct acidity of a coffee may not require the same cup material as a service aiming to create a rounder and sweeter perception.

Still, it would be more appropriate for any changes to be tested with the business's own customers and coffee before direct implementation.

How can cafés test this?

Implementing the research in a business does not require an expensive laboratory.

A café can conduct a small customer test by serving the same coffee with the same recipe, temperature, and volume on two different cups or sleeves in a controlled manner.

The questions can be kept simple:

How is the perceived acidity?
How is the sweetness?
How is the aftertaste?
How comfortable is the cup?
Does overall preference change?

However, the coffee's recipe, temperature, and serving volume must remain constant in the test. Otherwise, it will not be possible to separate the cup effect from the coffee preparation difference.

Also, simply asking "which one did you like more?" may not be sufficient. Aesthetically more beautiful cups may also consciously or unconsciously influence taste evaluation.

For this reason, participants in the new study were tested with their eyes closed.

We must not forget the operational side

Not every cup with sensory benefits may be commercially correct.

Textured ceramics may be more breakable. Special sleeves may increase costs. Rough surfaces may make cleaning difficult. Different cup formats may complicate the service standard for baristas.

On the take-away side, sleeve materials must also be evaluated along with supply, recycling, and waste management.

Therefore, the right decision for a café should consider not only the sensory outcome but also four areas together:

perception, ergonomics, operation, and cost.

Stafflink's view

The most valuable aspect of this research is not concluding that "a smooth surface makes coffee better."

Such a definitive result would already be stronger than what the research supports.

In our view, the main lesson is that the café should not think of its service equipment independently of the coffee.

After the barista has correctly applied the recipe, the cup, sleeve, and even the table where the coffee is consumed are part of the experience.

However, this area is very open to marketing claims. A cup manufacturer claiming "a cup that reduces acidity" or "a surface that increases sweetness" using a single academic study goes beyond the existing evidence.

A healthier approach for businesses is to use the research as a design hypothesis and test it with their own coffee.

Because the taste of coffee still primarily comes from the beans, roast, water, and extraction.

Touch may be one of the elements that can subtly change how this taste is interpreted in the customer's mind.