Not just any old whisk

For cappuccino lovers, the light, frothy milk on top – the crowning glory of this ever-popular hot drink – is no less important than the coffee itself! Whether one prefers a towering pile of stiff foam or a froth with a creamier consistency… tastes differ widely. And many more variations can be created through different preparation methods. The team at the PCV Group know this well, as their everyday work deals with stages of these systems – from the initial product idea to the finished product, from small improvements to newly-designed systems, and from consumer products to professional machines.

The state of the art – what can foam do?

For around six years now, PCV has been perfecting products used for foaming milk. The very first requirement for all clients in this area is the quality of the froth. Very often, they want to improve the consistency or increase the temperature. In order to determine the state of play at the beginning of a project, a standardised measurement approach is used – a tool developed over several years to highlight potential areas for optimisation.

The customer is always right – who operates the machine?

The target group of the milk whisk essentially defines exactly what is required: consumers want a good quality of milk foam (which, by the way, they often perceive as being too cold), without having to painstakingly clean numerous tubes and assorted parts of a machine afterwards. Things are very different in the food service industry; to create the perfect, easy-flowing milk foam, which has even become an art in itself already (#latteart), professional baristas must follow a tedious cleaning process. They don’t mind if the foam on the first cup of coffee of the day does not quite reach its optimal temperature, as the system is still cold.

From simple to complex – where to start, where to end up?

Particularly for home use, and considering consumer comfort, clients are looking for the simplest possible systems that deliver perfect results right from the start. On the other hand, machines used in the professional sector can be a little more complex. The range of milk foaming systems spans to the extremes. For example, in one case, PCV worked with a client to develop a completely tubeless system for a consumer product. It is a breeze to clean it, and the system is almost unbeatable in terms of user-friendliness. Although the frothed milk is generally a little stiffer with consumer products, in this case the quality of the milk foam is also good.

For another client, the sheer perfection of the foam was the goal, and even though the team already has a wealth of fundamental knowledge in the area of milk foaming, it certainly went the extra mile in this case. To fully understand what happens to the proteins, they consulted a team of university experts, and examined the entire design of the machine down to the smallest detail. Accordingly, of course, every in-house skill played a role – from heating to steam production. At the end of the day, however, whether simple or complex, both systems have to be absolutely reliable.

Raw material and patents – what does one have to bear in mind?

(Almost) every milk is different, and not all milk can be frothed. Plant-based milk products are a big challenge for most devices. Indeed, despite all innovation, there is currently no universal milk foaming solution in sight. Protein and fat-content also affect the quality of the milk foam, and the question of achieving the right temperature is a real balancing act. Very often, milk foam is perceived as too cold, yet it should certainly not be too hot, as protein molecules break down above 70°C and the milk foam collapses. Ideally, the temperature should lie at the upper end of the 60–70 °C range. In addition to the challenges that confront us as developers in terms of the medium we are working with, the team must maintain a good overview of things in the huge ocean of patents.