Dr Janet Cotton is a distinguished metallurgist and materials engineer, renowned for her expertise in solving complex engineering challenges across various industries. She is the founder and managing director of One Eighty Engineering Solutions, Africa’s most widely scoped ISO 17025:2017 accredited materials and metallurgical testing laboratory.
Dr Janet Cotton, founder of One Eighty.
How would you describe the value of forensic and materials analysis to the wine industry value chain?
Winemakers are not trained in any way to select winemaking equipment on the materials of construction and methods of construction. As such, they are delivered to the suppliers of the winemaking equipment to follow the correct methods and procedures and select the correct materials.
Unfortunately, with the lack of skills and understanding of critical importance of correct materials selections, applications like pickling and passivation of winemaking equipment, and executing on the correct welding procedures duly qualified in an accredited laboratory, the winemakers are delivered to poor fabrication methods and poor selection of materials, resulting in losses of their product which in many cases have taken many months to develop.
If winemakers could enlist the services of a metallurgical engineer to assess before purchase of equipment to ensure that all the correct procedures have been followed then they could dramatically mitigate the risk of loss of product and capital equipment not lasting sufficiently long in service.
What is the need for metallurgical forensics in the wine industry?
Root cause analysis (RCA) is the analysis of failures of machinery or equipment associated with winemaking, and is essential to determine why the equipment has failed and make better choices in the future. Learning from mistakes and making better decisions is better than replacing like for like and living with the same problem which could compromise the product quality as well as throughput or yield.
We learnt from visitors from France at the recent Inaugural RCA Africa conference in March 2025 that there are 100 metallurgical engineers working on RCA just on metal alloys in a small town in France. Overall the company has over 1000 employees.
I think the need is bigger than we think, due to a lack of awareness of metallurgical engineer and materials engineering as a profession, and that many failures go by the way side people accepting that this just happens, rather than taking a proactive approach to find out exactly why failures occurred so as to prevent them in the future.
I think the wine industry simply does not know that this is an option open to them, and furthermore don’t understand the value, which is in the long term to conserve the product, get a long life span out of capital equipment and also enable throughput of product. Life of capital equipment, product preservation and throughput all come down to the correct application of metallurgical and materials engineering. Many winemakers may just be dealing with what they think are frustrations that they have to live with but that is not the case, expertise exists to improve these three things which are at the core of the profitability and longevity of a winery.
What common risks faced by the wine industry can be addressed through this field?
There are many risks. One is associated with wine tank fabrication and the proper welding of the steel plates to make up the tanks. The tanks depending on their size are subject in respect of the occupational health and safety act to be fabricated with qualified welding procedures, where the qualification occurs by means of mechanical testing at an accredited laboratory. This is not happening.
Secondly, stainless steel used in the food and beverage industry MUST be pickled and passivated after fabrication, since the protective coating on stainless steel equipment that gives it corrosion resistance is compromised during fabrication. In order to re-instate a homogenous, intact and contaminant-free coating for the best possible corrosion performance, the entire fabricated item should be properly pickled and passivated as described in the International Standard A380 for Pickling and Passivation.
In the absence of such a treatment, the product exposed to the equipment will become contaminated with continued use with devastating outcomes for the winemaker.
What diagnostic tools and methods are typically employed during a forensic analysis in a cellar or winery?
All metallographic techniques are used. If welding is suspected to be a problem, then samples will be cut from the welded joint and examined under a microscope. If corrosion mechanisms such as stress corrosion cracking are suspected, then samples will be cut and light microscopy as well as scanning electron microscopy will also be used to diagnose the corrosion mechanism. Mechanical testing may also be conducted, such as tensile testing, bend and impact testing to check that welding procedures were qualified correctly. Corrosion testing might also be used to test whether the welded joint is susceptible to grain boundary attack of the microstructure which would indicate that the incorrect welding procedures and essential variables have been used during fabrication, and that indeed the welding procedure was not qualified.
How can wineries avoid or minimise the risk of catastrophic failures?
Becoming aware of the importance of metallurgical and materials engineering, by realising that the equipment that they are buying is made of metal, usually stainless steel, and that stainless steel is not a miracle material that you can do anything to and it will survive and perform. Stainless steel is corrosion resistant, not corrosion immune, and if not selected correctly and subjected to the correct fabrication process it will not perform and its corrosion resistant properties can almost be rendered null and void.
Who should wineries consult if they have questions or concerns?
One Eighty Materials Engineering Solutions (Pty) Ltd is the ONLY commercially supported consulting engineering practices in South Africa with an accredited laboratory to the international standard ISO 17025 in Africa. The laboratory is also the most widely scoped laboratory in Africa which means we are accredited for the most test methods. We have extensive experience in the food and beverage industry, advising on materials, qualifying welding procedures, and conducting root cause analysis.
We should be consulted when buying winemaking equipment so as to ask the right questions and request the requisite documentation to indicate that fabrication processes have been followed to ensure longevity of the equipment, prevent product contamination and enable the requisite throughput.
