Aseptic premiere for milk at Pyatigorskiy

UHT milk remains Pyatigorskiy Dairy’s main product. “Demand on the Russian market is growing year by year,” says the dairy’s president Konstantin Sukharev. Retailers prefer UHT milk because of its longer shelf life. Besides that consumers prefer it because their buying habits have changed: They want to spend less time on shopping, so they buy larger quantities to have on hand – which means the products have to keep longer. In southern Russia, summertime temperatures can rise above 40 degrees Celsius (104 degrees Fahrenheit). It would be complicated to keep larger quantities of fresh milk in the cold chain. And then there’s the fact that UHT is the only way to go for transporting milk to other parts of the vast country.

“At the same time, PET bottles are becoming increasingly popular as a packaging material for milk,” explains Konstantin Sukharev. “So far, though, they have only been used for fresh milk. Now we have combined PET packaging and UHT milk – and for that we chose a Krones aseptic line.” PET has several things going for it as a packaging material:

• Consumers find PET bottles visually appealing and easy to use.
• Bottling and packaging in PET can cost half as much as packaging in cartons.
• A PET filling line is far more flexible than a carton packaging line since switching to different container sizes and shapes entails less effort and cost. And that enables producers to respond flexibly to market demands.
• Carton packaging, on the other hand, is more susceptible to damage during transport – up to 1.5 percent of carton packaging is compromised in the delivery process.

Modern technology

The PET line from Krones is designed for aseptic filling of low and high-acid products. This versatility is important for the dairy because of the very different pH values of the two products it has so far run on the line: Milk has a pH of around 6.8 while kefir’s is around 4.3. Pyatigorskiy fills the UHT milk into transparent containers and the kefir into round, opaque white containers. Both container varieties have a volume of around 900-milliliters. The preforms used for the white kefir bottles have an integrated low-level oxygen and UV barrier.

When changing over from kefir to milk, the PET-Asept D line is properly cleaned and sterilized with hydrogen peroxide (H₂O₂) in order to prevent contamination of the milk. Even the considerably higher viscosity of kefir does not present a problem for the aseptic block. It can operate for 144 hours at a stretch before a two-hour sterilization is required. “It’s a great line,” says Konstantin Sukharev. “It runs outstandingly well with just two operators per shift. And Krones Academy coaches trained those operators on site.”

Options for expansion

The company intends to gradually expand the range of products and containers processed on the PET line. It is already set up to fill yoghurt smoothies with and without fruit bits and to handle 1.3-liter and 0.3-liter bottles. The dairy also wants to bring a square-shaped bottle to market sometime in the future, with higher barrier properties that should increase the shelf life of UHT milk to an entire year. “Some regions of Russia in the north and far east are logistically impossible to reach for as much as nine months of the year because of their extreme climates. And transport from Pyatigorsk to these areas takes 21 days as it is. So, a longer shelf life than the 45 days you generally get with normal preforms definitely makes sense,” says Konstantin Sukharev.

The PET aseptic line was validated and went into operation in January 2019. “The Krones line has opened up a new market segment for us. UHT milk in these containers is a brand new and unique product on the Russian market,” says owner Vladimir Kayshev. “We are confident that we will be operating at full capacity on the new line within a year – once the products have really hit the market.”