Technical Yearbook 2024

SEPTEMBER

E-aphrom – a digital sensor for secondary fermentation By Guilherme Costa

The e-aphrom is Winegrid’s latest solution for monitoring the second fermentation stage in sparkling wines produced via the Champenoise method. This article presents the e-aphrom’s working principle and interface and provides an example of the device’s application in a real scenario. This technology represents a step forward towards the future of winemaking. Introduction With the wine industry increasingly focusing on efficient monitoring systems, innovative technologies have emerged. These advancements, driven by the need for production optimisation, quality control and safety, have paved the way for the application of IoT (Internet of Things) monitoring systems. These systems, powered by a network of diverse sensors, gather, analyse and store crucial data, providing invaluable assistance to winemakers at various stages of the winemaking process. Recently, some companies have been developing IoT monitoring systems with sensors designed to measure pressure, liquid level and density, among others. Winegrid’s Research and Development team comprises several specialists working on AI-based platforms that help winemakers monitor different real-time parameters. Two of its more recent sensors aimed at sparkling wine production are the e-aphrom and e-charmat. These present remote solutions in real-time that allow pressure monitoring during the secondary fermentation. The secondary fermentation creates bubbles in sparkling wine. The chemical reaction transforms sugar into alcohol and carbon dioxide. The two more popular methods include the Charmat and the traditional Champenoise methods. The main difference between the two approaches is the stage at which the secondary fermentation takes place. In the Champenoise method, after adding the sugar and yeast, the wine is transferred to a bottle and sealed to imprison the CO 2 . Some winemakers point out that this methodology has the advantages related to a longer time in the bottle, such as adding more complexity to the wine due to a higher surface area for wine and yeast exchange and allowing a more gradual process of stirring than centrifugation methods. In the Charmat method, secondary fermentation occurs in a large, sealed and pressurised tank. Only after the end of the process is the wine transferred to a bottle. This is less time consuming and an easily scalable process.

Several parameters are important to monitor. Increased pressure is a strong indicator of the start of secondary fermentation. The e-aphrom is an online system that acquires pressure and temperature in real-time. This solution helps monitor secondary fermentation by storing the data in a cloud platform and displaying it on a dashboard. It allows data to be compared, previous values to be revisited, and the system to interact with it via manual information insertion. This dashboard can send notifications in case any threshold is crossed. Technical features of the e-aphrom sensor Sensor characteristics The e-aphrom’s pressure monitoring sensing mechanism is based on piezoresistive behaviour. The sensing layer is made of conductive material that changes resistance when stretched. This change in resistance is detected, exhibiting an output voltage proportional to the stimulus. The device

FIGURE 1. Working principle of the pressure sensor.

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TECHNICAL YEARBOOK 2024