Smart bungs

Abstract

Levels of sulfur dioxide (SO2) are vital during secondary fermentation and throughout the maturation of wine to prevent oxidation and to protect the wine from spoilage as it develops. The current methods for monitoring SO2 concentration utilise relatively large (up to 100 mL scale) samples and require regular human intervention. What is needed is a system that can monitor SO2 in real time using low volumes and is sufficiently low cost to be embedded within every barrel.

Summary

Australia is known around the world for its excellent wine. Throughout the fermentation and maturation stages of wine production, several important parameters must be monitored and controlled to ensure both quality and reduction in product spoilage. One of these variables is the sulfur dioxide concentration (SO2).

SO2 is vital for producing good quality wines as it is not only used as an anti-oxidant, but it also has excellent antimicrobial properties. The current method for monitoring SO2 requires samples to first be removed from the barrel and tested using a lengthy several step process which not only takes time, but also large volumes and with a requirement for opening the barrel with possible exposure to air. The result of this analysis is limited, providing the winemaker with just an indication of the state of the wine at that specific time point and provides no information about the path taken to get to this point. Additionally, due to time and money constraints, not all barrels are regularly tested. This means that any problems that occur in the untested barrels such as spoilage may impact in terms of overall blended wine quality and a downgrading of the wine and consequently a reduction in income.

The ultimate objective of the “Smart Bungs” project was to design a bung embedded with optical fibres which can be used to test several important parameters in near real time so that winemakers can constantly monitor the wines throughout the entire wine production process. This would allow the winemaker to take immediate action to remedy any potential problems before the barrel becomes unsalvageable. The integration of the optical fibre based system into the bung would also allow wine samples to be extracted directly from the barrels and avoid the human contact, time and exposure to air; which occurs using existing testing methods. It would also be possible to embed a bung into every barrel so that every single barrel could be monitored individually rather than periodically testing a representative sample.