Operator’s Diary / UHTExclusive talk · 2026
A portrait from the industry / From the production floor

36 years at the helm of UHT. Still with first-day excitement.

We talked with Muzaffer Çelik about the UHT process, the finer points of being an operator, the problem-solving culture on the shop floor and the production experience built up over the years.

Food Engineer Talks · Operator’s DiaryExclusive talk · Muzaffer Çelik
Muzaffer Çelik — exclusive talk portrait
Muzaffer ÇelikUHT operator · production team leader · operator trainer
From the talk / Featured view
An operator who keeps the production running in their head after it has ended, analysing it almost like a post-match analysis, is a good operator for UHT.
Muzaffer ÇelikUHT Tetra Pak Production and Packaging Supervisor and Trainer, Fomilk36 years of UHT shop-floor experience

As soon as I announced on LinkedIn that UHT would be the first topic of “Operator’s Diary” — the section I am preparing about our operators, the backbone of food production — Mr Muzaffer Çelik left a comment under my post the very same day: “This topic is right up my street. I have 36 years of experience and I would like to talk with you.” So, just before Food Engineer Talks went live, we had an enjoyable conversation with him.

Editorial note · How this talk was prepared

This talk was prepared for publication on the basis of a video call held over WhatsApp between Food Engineer Talks (FET) and Muzaffer Çelik, and the written question-and-answer notes shared by the guest.

FET prepared this content to share the shop-floor experience accumulated in food production and to make technical subjects visible. This exclusive talk is not a promotion prepared as paid advertising, sponsorship, product placement or a commercial collaboration. The company, brand, machine, role and experience details mentioned in the talk are based on the guest’s own statements and on what he conveyed during the conversation; they do not mean that any product or service is recommended or endorsed by FET.

In this publication, the distinction between commercial advertising and covert advertising set out in Article 61 of Law No. 6502 (Türkiye) has been observed. The company, brand and technical-term links are there to inform the reader. This note relates only to how this talk was prepared and published.

His eyes still light up at the mention of UHT

The excitement in his first message carried straight through into our conversation. Mr Çelik is remarkably quick and eager. Better still, although he has worked in the UHT process for 36 years, when the subject turns to UHT his eyes still light up and his face still breaks into a smile, just like on day one.

I was genuinely happy to have met him.

To work in the same field for 36 years and still be excited, still be energetic, still tell work stories with passion… That alone is a lesson for anyone who gets bored of everything quickly.

Although he describes himself as having “learned on the job”, over the years he has kept reading, researching and improving himself. His way of speaking, his calm and his courtesy also stand out. He put both of his children through university abroad, and he supports them in continuing to postgraduate study. That his children have the higher-education opportunity he never had is a particular source of pride for him.

36 years on the line

Today Mr Çelik works at Fomilk as UHT Tetra Pak Production and Packaging Supervisor and Trainer. His career began in 1987 as a machine operator under the roof of Gülüm Süt–SEK Süt, where he stayed until 1999. Then came four years at Kaysüt and 11 years at Yörsan as shift leader; two years at Sütaş Tire, three years at Teksüt and one year at Akbel as production team leader. Today he is still on the production floor.

Looking back over his 36 years of experience, he underlines one thing in particular: working with company owners and managers who love milk and are themselves immersed in it, he says, gives a person a special kind of drive and joy in the work.

How do you recognise a good UHT operator?

When I asked him how he recognises a good UHT operator, he drew a very memorable comparison. Like people who go over the key moments again and again after a football match and analyse the game, he said, the operator who keeps running through what went well and what went badly after the production has ended, and who carries on analysing it, is a good UHT operator.

“An operator who keeps the production running in their head after it has ended, analysing it almost like a post-match analysis, is a good UHT operator.”

Young people need to be drawn into production

One of the important parts of our conversation was about the young people entering the sector. According to Mr Çelik, companies and managers have an important role to play if young people are to gain the motivation and passion that production calls for.

He particularly stressed that young employees need close attention, and that through good-quality training, workshops and hands-on practice they should be taught not just “which button to press” but also the technological and scientific side of production. Because the more a person understands the reason behind the job they do, the more their view of that job changes.

Lessons from production that are never forgotten

When I asked about a memory from his production years that had upset him, he described how, because of a mistake in the purchasing and quality processes, a cocoa unsuitable for UHT chocolate milk production was used and sedimentation appeared in the products over time. The lesson he took from it is clear: with a new raw material or application, trials and shelf-life monitoring must be carried out systematically and in full.

One of the moments he is proud of is raising line efficiencies after he started at the Sütaş Tire plant. That Mr Muharrem Yılmaz congratulated him in person after this work holds a special place in his memory.

When I asked where the same energy and motivation come from every day, he spoke of his belief in the importance of the work he does. He thinks producing safe food that is fit for human health matters a great deal; that is why he wants to know and understand not only the part he is responsible for, but as far as possible every detail of production.

Experience36 years on the UHT and aseptic production floor
TodayFomilk · UHT Tetra Pak Production and Packaging Supervisor and Trainer
FocusProcess discipline · quality · hygiene · operator training
Question 01Operator’s Diary

What is UHT, and why does it matter?

Muzaffer Çelik

“UHT is based on raising milk to a high temperature within a very short time and then cooling it again. The aim is to bring the microorganisms in the product under control, so that the product becomes safe and keeps for a long time. Here temperature, time, hygiene and process control are very important.”

FET technical note

According to the UHT definition in the Turkish Food Codex, the treatment is carried out at a temperature of not less than 135 °C with a suitable temperature-time combination, and microbiological stability at room temperature is targeted by sealing the product aseptically. In industrial practice, depending on the product’s properties and the system used, a heat treatment in the range of about 135–150 °C, generally lasting a few seconds, can be applied.

UHT is especially common in low-acid liquid foods such as milk, flavoured milk, cream and plant-based drinks. The main reason is that, while giving a safe product with a long shelf life, it can limit sensory and nutritional changes as far as possible by applying a high temperature for a very short time.

In indirect systems the product and the heating medium do not come into contact; heat is transferred through a heat-exchanger surface. Tubular systems can be used for milk and milk-based drinks as well as for products with a certain viscosity or particulate structure. In direct systems, clean steam is brought into direct contact with the product by injection or infusion; because the product can be heated and cooled very quickly, the total heat load can be reduced.

Tetra Pak TBA/8 – 1000 ml Slim aseptic filling machine
Tetra Pak® TBA/8 – 1000 ml Slim aseptic filling machine.
Question 02Operator’s Diary

When you first started operating a Tetra Pak machine, what did you find hardest?

Muzaffer Çelik

“At the beginning, the sheer number of parameters and points you have to keep track of on the machine can be hard going. But over time you start to get to know the machine’s sound, its behaviour and the way it runs. After a while you can pick up, from certain signs, a problem that may arise on the machine before it has even appeared.”

Question 03Operator’s Diary

What have your 36 years of experience taught you?

Muzaffer Çelik

“I learned that the most important thing is attention and discipline. In this job there is no such thing as ‘it will be fine somehow’. Because the product we make is directly related to human health. Our priority must always be a safe, high-quality product.”

Question 04Operator’s Diary

In your view, what should a good Tetra Pak operator be like?

Muzaffer Çelik

“Knowing how to operate the machine is not enough. They must have process knowledge, follow the hygiene rules, carry the responsibility for the work they do and communicate well with their team. They should also always be open to learning.”

Question 05Operator’s Diary

How do you tell that something is wrong with the way the machine is running?

Muzaffer Çelik

“Experience matters a great deal here. Once you have learned the machine’s normal running sound and movements, you can notice a difference straight away. A small noise, a change in filling behaviour or a difference in product flow can show you that something is not right.”

Question 06Operator’s Diary

Why is hygiene so important in UHT production?

Muzaffer Çelik

“Because the product goes straight to the consumer. The purpose of the UHT process is not just to make the product, but to get it to the consumer safely. That is why the cleaning, sterilisation and process rules have to be followed in full.”

Question 07Operator’s Diary

What do you see as the biggest difference between an experienced operator and a new one?

Muzaffer Çelik

“An experienced operator does not just deal with a problem once it has occurred; they try to notice in advance that a problem may occur. But the young operator has an important advantage too: they can be more open to learning and to new technologies. When experience and the energy of youth come together, the result is very good.”

Question 08Operator’s Diary

What are the points that need the most attention on Tetra Pak machines?

Muzaffer Çelik

“You need to keep a constant watch on the machine’s settings, the product flow, the filling system, the packaging operation and the hygiene/sterilisation conditions. An operator should follow not only the values on the screen but also the machine’s overall running behaviour.”

Question 09Operator’s Diary

Which Tetra Pak filling machines have you most enjoyed operating?

Muzaffer Çelik

“The one I most enjoyed working with was the Tetra Pak® TBA/8 – 1000 ml Slim. Among the new-generation machines, the A3 series — such as the Tetra Pak® A3/Flex and the Tetra Pak® A3/Speed — catches my eye.”

FET · Machine note

The Tetra Pak® TBA/8 – 1000 ml Slim is one of the long-serving aseptic filling platforms of Tetra Pak. Tetra Pak’s own history content states that the 1-litre Tetra Brik® Aseptic 1000 Slim package was used with the TBA/8 aseptic filling line. This format has become closely identified with liquid foods, UHT milk in particular, for which a long shelf life at room temperature is targeted.

The Tetra Pak® A3/Flex brings out the flexibility side of today’s aseptic filling machines; it offers solutions for switching between different package types, sizes and closure options. QuickChange™ and volume-conversion options make it easier to adapt to different market needs on the same machine.

The Tetra Pak® A3/Speed, for its part, is a platform that targets high capacity, operational efficiency and aseptic food safety together; it is positioned for both portion-size and family-size packaging applications.

Question 10Operator’s Diary

What would you like to say to young people about this profession?

Muzaffer Çelik

“They should be patient, and not stop at just learning the job; they should try to understand the reason behind it as well. Knowing which button to press on the machine is one thing; knowing why you press that button is another. They should keep improving themselves.”

The last word
“For me this profession is not just about running a machine; it is about contributing to a safe, high-quality product that touches human health.”
Muzaffer Çelik