For more than a century, espresso technology has relied on a familiar combination of heat, pressure and time. But new research into ultrasonic extraction suggests that sound waves could offer an alternative way to accelerate coffee extraction—potentially reducing energy consumption while producing espresso-style beverages with room-temperature water.
The technology is still at the research and prototype stage, but its potential implications for coffee equipment manufacturers, cafés and commercial coffee processors are attracting growing attention.
From Heat and Pressure to Ultrasonic Energy
The modern espresso machine can trace its technological roots to the late 19th century. Early machines were designed to solve a simple commercial problem: coffee preparation was too slow when cafés faced large numbers of customers.
Traditional espresso brewing uses heated water, pressure and finely ground coffee to extract soluble compounds within roughly 30 seconds. Heating water increases molecular movement and accelerates the extraction process, while pressure forces water through a compact bed of coffee grounds.
Cold brewing takes the opposite approach. It eliminates heat and uses much longer extraction times, often requiring 12 to 24 hours.
Ultrasonic extraction introduces a third approach: instead of relying primarily on heat to accelerate extraction, it uses high-frequency mechanical energy.
How Does Ultrasonic Coffee Extraction Work?
Ultrasound consists of high-frequency pressure waves. When these waves travel through water, they can create microscopic bubbles through a phenomenon known as cavitation.
These bubbles rapidly expand and collapse. Near a solid surface such as a coffee particle, the collapse can generate intense localized turbulence and micro-jets.
In coffee extraction, these effects can:
Disrupt the surface of coffee particles
Create microscopic fractures
Improve water penetration into the grounds
Increase mixing around coffee particles
Remove concentrated liquid from the particle surface
Accelerate the transfer of soluble compounds into the brewing water
In other words, ultrasonic energy can provide mechanical assistance to the extraction process rather than depending entirely on elevated water temperature.
This is particularly significant because coffee grounds contain a complex mixture of oils, acids, sugars, aromatics, caffeine and other soluble compounds. Brewing is fundamentally the process of transferring those compounds from the solid coffee particles into water.
The Sydney Research: Espresso Without Hot Water
Researchers at the University of New South Wales in Sydney, including chemical engineer Francisco Trujillo, investigated whether ultrasound could accelerate coffee extraction without conventional heating.
An earlier stage of the research, published in 2024, demonstrated that ultrasonic energy could dramatically shorten cold-brew-style extraction. The resulting beverage, however, was relatively dilute and did not reproduce the concentration associated with espresso.
The more difficult challenge was therefore to produce an espresso-style beverage using room-temperature water.
The research team modified a commercial Ascaso Uno espresso machine and retained its conventional portafilter basket. Instead of putting an ultrasonic device directly into the coffee and water, the researchers used a mechanical arrangement to vibrate the basket.
A steel horn with a 6 mm tip was positioned at the basket’s resonant location. The ultrasonic transducer operated at approximately 42.6 kHz, well above the range of human hearing.
This approach allowed the ultrasonic energy to reach the coffee bed through vibration of the basket itself.
Espresso-Style Extraction in 2–3 Minutes
The researchers tested several variables, including grind size, brew ratio, ultrasonic power and extraction time.
According to the study described in the source material, the ultrasonic system was able to produce espresso-strength coffee using room-temperature water in approximately 2 to 3 minutes.
The extraction yield reached the range generally associated with specialty coffee brewing, while total dissolved solids were also within an espresso-style concentration range.
One of the most important parts of the experiment was the control test.
The researchers used the same basic brewing conditions but switched off the ultrasound. Under those conditions, room-temperature water could not achieve the same espresso-level extraction.
This suggests that the ultrasonic energy was not simply an additional feature. It was playing a central role in accelerating extraction.
Energy Consumption Could Be a Major Advantage
One of the most interesting implications for the coffee equipment industry is energy consumption.
Conventional espresso machines typically maintain water at elevated temperatures, with boilers and associated components consuming electricity during operation and standby periods.
The ultrasonic system removes the need for conventional boiler heating.
According to the research described in the source material, the ultrasonic approach used approximately 75% less energy than conventional espresso brewing when beverage strength was matched.
For a single household user, the absolute energy savings may be relatively modest. The potential impact becomes more significant in commercial environments.
A busy café may prepare hundreds of espresso drinks every day while maintaining a hot-water system for many hours. Reducing the need for continuous water heating could therefore affect both operating costs and equipment design.
The technology could also have implications for industrial coffee production.
Potential Applications in Ready-to-Drink Coffee
The potential benefits extend beyond cafés.
Coffee manufacturers producing bottled or canned beverages often need to extract coffee at large scale before the resulting concentrate is processed, cooled, diluted or packaged.
If coffee compounds can be efficiently extracted using room-temperature water, manufacturers could potentially reduce or eliminate some heating and cooling requirements during the extraction stage.
This could have implications for:
Ready-to-drink coffee production
Coffee concentrates
Cold coffee beverages
Industrial extraction systems
Energy-efficient commercial brewing
Compact coffee equipment
However, these possibilities remain areas for further development rather than established commercial applications.
Does Ultrasonic Coffee Taste Like Espresso?
Energy efficiency alone would not make the technology commercially attractive if the resulting coffee tasted significantly worse.
The research therefore compared ultrasonic coffee with conventionally brewed espresso using chemical measurements and sensory testing.
The chemical analysis reportedly found no significant differences across the measured markers between the ultrasonic and conventional espresso samples.
Sensory testing involving approximately 100 participants also found no significant overall preference between the two espresso samples.
In other words, participants did not consistently prefer the conventional espresso over the ultrasonic version.
Interestingly, the research also examined filter coffee. In that comparison, participants preferred the ultrasonic version.
The researchers associated this result with differences in extraction behavior, suggesting that ultrasonic energy may provide greater control over the release of soluble compounds from coffee grounds.
Why the Technology Matters for Coffee Equipment Manufacturers
The significance of ultrasonic extraction goes beyond replacing a heating element.
If extraction can be controlled through ultrasonic power, grind size and brewing time rather than primarily through temperature, coffee machines could potentially become simpler and more compact.
A future ultrasonic brewing system could potentially consist of:
A water reservoir
A coffee chamber or basket
An ultrasonic transducer
A mechanical coupling system
Electronic power controls
The absence of a conventional boiler could reduce the size and weight of the machine while eliminating components associated with heating and temperature management.
It could also reduce warm-up time and potentially simplify maintenance related to heating systems and scale buildup.
A Chinese Patent Points Toward Commercialization
The research is also notable because a Chinese patent application has emerged around ultrasonic cold coffee extraction.
The source material identifies CN223900158U, titled as an ultrasonic coffee cold-extraction device, with the application dating to March 2025 and publication in February of the following year.
The described system includes an ultrasonic generator, transducer, amplitude transformer, coffee and water chamber, and mechanical stirring mechanism.
Importantly, the patent is described as a Chinese utility model, rather than a full invention patent.
That distinction matters.
A utility model generally focuses on the structure or configuration of a product and undergoes a different and less extensive examination process than an invention patent. A patent filing therefore should not automatically be interpreted as proof that a commercially viable product already exists.
Nevertheless, the document is significant from an industry perspective because it focuses on making ultrasonic extraction equipment more suitable for domestic use.
The research question is no longer simply whether ultrasonic extraction can work in a laboratory. It is increasingly becoming an engineering question: Can the technology be made compact, affordable, reliable and easy enough for everyday coffee brewing?
From Laboratory Technology to Coffee Equipment
The current ultrasonic system remains far from replacing conventional espresso machines.
The research prototype requires specialized components and currently takes around 2–3 minutes to produce an espresso-style beverage, compared with approximately 30 seconds for conventional espresso.
There is also no indication from the source material that ultrasonic espresso machines have already reached widespread commercial production.
The Chinese utility model patent is likewise not evidence that a mass-market product has been manufactured.
These limitations are important. Laboratory performance does not automatically translate into commercial success.
Manufacturers would still need to solve questions involving durability, acoustic and mechanical design, food-contact safety, noise, vibration control, cleaning, component costs, consistency and user experience.
Could Ultrasound Become the Next Major Coffee-Brewing Technology?
For roughly 140 years, espresso equipment development has largely focused on improving the same fundamental variables: temperature, pressure and extraction time.
Ultrasonic extraction introduces a different variable—mechanical energy delivered through high-frequency sound.
The research demonstrates that room-temperature water can be used to achieve espresso-style extraction when ultrasonic cavitation is carefully controlled. It also points to potentially substantial energy savings and demonstrates sensory results comparable to conventional espresso under the tested conditions.
For the coffee industry, the most important development may therefore not be the immediate replacement of today’s espresso machine.
Instead, it may be the opening of a new engineering pathway.
A future coffee machine may not need to spend most of its energy heating water. It may use controlled mechanical energy to accelerate extraction instead.
For cafés, coffee manufacturers and appliance companies, that possibility raises several important questions: Can ultrasonic systems become faster? Can they become smaller and quieter? Can manufacturing costs be reduced? Can extraction profiles be precisely controlled? And can the technology deliver consistent results at commercial scale?
Those questions remain unanswered.
But after more than a century of incremental improvements to heat and pressure-based brewing, ultrasonic extraction suggests that the next major change in coffee equipment may come from a completely different source: sound.
