A definitive guide on hot-fill process in the beverage industry

With the successful development of the beverage industry, the way to preserve and types of packaging has become more and more diversified. Generally, in the current market, we can find many different shapes, sizes, and materials of bottles parallel to advanced filling technologies.

Among various methods, hot fill is one of the most primary methods in protecting as well as extending the beverages’ shelf life. Hot filling is outstanding in its competitive advantages and optimization in processing.

In short, this article will state the necessary information to help you gain background knowledge of hot fill. In addition, we also provide how hot filling works, a typical example drink, and the differences between hot fill and other methods.

Hot fill is one of the most primary methods in protecting and extending the beverages’ shelf life

What is hot fill?

Hot filling is a method used extensively in the modern food and beverage industry. It is defined as the process of heating the products and then being cooled down immediately.

What are the details?

As the name suggests, the hot filling method manufacturers use to store the drink and deliver it to the packages when the beverage is exceptionally high. This process is fulfilled entirely by advanced machines with the bulk of beverage bottles.

How does the hot filling process work in general?

The hot filling process is divided into four main stages, including:

• Stage1: Heating the beverages
• Stage 2: Placing the beverages into different containers (often pre-warmed)
• Stage 3: Capping or closure the containers (to ensure container headspace’s pasteurization)
• Stage 4: Keep drinks cold again

At first, the drinks will be heated up to 194 degrees Fahrenheit for at least 15 seconds (typically from 15s to 30s) for removing the harmful microorganisms from the products. With this environment, we can create a “Commercially Sterile Product” by preventing bacterial development. After that, the hot fluid is filled into containers of different sizes.

In the next step, these drink bottles will be capped firmly in sterilization, holding the temperature around 82-85 degrees Celsius for approximately 2-3 min in the big containers. When the packaging is completed, these containers will often be placed on the cooling tunnels to minimize the thermal degradation of the drinks.

How does the hot filling process work in general?

What kind of bottles to use often?

Nowadays, the majority of manufacturers can provide diversified types of containers for the hot filling process. Every single kind of bottle will be fitted with different types of beverages and different materials. However, there are some common ones:

PET bottles are the best for Hot fill process

• PET
• HDPE
• NFCs
• Glass bottles
• Jars
• Plastic containers
• Viscous fruit and vegetable-based products

By contrast, PET bottles are considered the most popular containers for hot fill. Besides the reasonable price compared to their convenience and benefits, PET bottles are born to be appropriate with the hot temperature and beverage protecting functions.

While glass bottles had traditionally been used for the hot filling process, PET bottles can be unique and more effective by withstanding the heat involved, together with hot filling without becoming deformed or collapsing.

Moreover, these bottles are growing in popularity because of the economic problem: plastic is generally less expensive than glass.

Look at the list of some specific benefits of PET bottles:

• Wide range of bottle design
• 100% recyclable material, be environmentally friendly
• The great flexibility of size
• Occupation of adequate exposure and space optimization
• Attractive appearance, shining and transparent like glass but unbreakable
• Perfect barrier: prevent permeability of water, oxygen, and carbon dioxide
• Appropriate characteristics to improve impulse buying

9 famous product lines that take advantage of the hot-fill process

To be more specific, the hot filling process is best suited for beverages with a pH index below 4.6. They are the non-alcoholic types of drinks with a massive market share because of customers’ satisfaction.

The hot filling process is suited for beverages with a pH index below 4.6

We can list 9 drinks types that often make use of hot fill to protect and increase the shelf life:

• Juices
• Nectars
• Soups
• Spreads
• Flavored waters
• Isotonic drinks
• Vegetable drinks
• Marinades
• Sports drinks

What are the advantages of hot fill for the beverage industry?

The hot filling process is the most optimal method for ensuring the quality and improve the life span of the beverage

Why do we have this statement?

To answer this question, Let’s clarify several outstanding features or benefits of the hot filling beverage process below:

Increasing the shelf life of beverages

The hot filling method can improve the using time by removing many microorganisms that could contaminate the drink. Without the presence of these bacteria, the beverage will be stored in the best environment.

Mainly, with the sterilization from the bottle to the cap, this process will minimize the damage of the gas or microbes from the natural air.

Making use of the hot-fill process to increase the shelf life of beverages

Give customers the trust of safety for your product

As mentioned above, Hot filling preserves the beverage at high temperatures and the sterilization process. As a result, there will be no need for harmful preservatives or other artificial additives. The customer can rely on the quality of products that remain as original as possible.

Remain healthy substances and good tastes

With the perfect protection of hot filling by natural method, it can reduce the external impacts on the beverages. Vitamins and nutrients are well preserved. In addition, the drinks can also keep the tastes with full flavors.

Using PET bottles with various benefits

Because the hot filing process primarily uses the PET bottle for containing the drinks. It results in many benefits in the economic problem as can be seen that the PET bottle is much lighter in weight compared to the traditional glass ones. Therefore, it is significantly easier to transport and deliver the drinks.

It’s not enough!

Not only do they have advantages in weight, but PET bottles are also more cost-effective than glass. On average, if you replace glass bottles with PET, you can save up to 30% on shipping costs.

Using PET bottles for hot filling with various benefits

Differentiate between hot fill and other methods

There are many different processing possibilities for preserving and packaging drinks into rigid or flexible containers in the beverage industry. Each manufacturer needs to choose the most suitable method for their business that fits the single beverage’s features.

Think about it:

Four popular methods are hot fill, cold fill, retort, and aseptic. At present, we will make clear for you these four basic concepts, the process and distinctions among them. However, due to the hot filling process described in detail, we would like to clarify the three others for you.

Cold Fill

Cold filing has a significant difference with hot fill: there is no involvement of high temperature. During the process, the manufacturers use cold methods for packaging and preserving the beverages.

From the beginning to the end of the process, the container is pressurized by cooling the drinks, then the cold product is loaded and placed in the cold containers. It is noticeable that the cold fill process requires sterilization, which would be either a dry or wet sterilization.

Juice, milk, and aerosol applications are some product lines that commonly use this method.

Retort Processing

Retort processing is not similar to a cold or hot filling. It’s not the story of using temperature at first. It only uses temperature in the last small stage. This method takes place when the producers fill non-sterile products in non-sterile packaging or hermetically sealed.

What’s next?

The packaging is delivered to a retort pressure vessel and then subjected to pressurized steam.

The beverage products are also put into high temperatures for a much longer shelf life than in the hot-filling method. It is the additional time that can considerably deteriorate the general quality of nutritional content in the drinks.

Retort processing is not similar to a cold or hot filling

Aseptic Fill

Among four popular methods, Aseptic is a desirable alternative to hot-fill since it doesn’t expose products to expand drinks by high thermal temperatures. To be honest, sometimes, the hot fill can cause vitamin, taste, color and texture degradation due to the scorching temperature.

Thereby, the aseptic process ultimately can ensure a better quality drink that can remain shelf-stable distribution. This process takes place smoothly with four basic steps, including:

• Step 1: Commercially sterilize and cool your beverages
• Step 2: Pre-sterilize the packaging or containers to ensure the double sterilization process.
• Step 3: Re-sterilized the external surfaces of the spout and the cap with VST (Vapor Sterilant Technology)
• Step 4: Your final packaging is an enclosed atmosphere that is free of microorganisms. In this stage, the filling process is completed. The cap will be hermetically sealed onto the spout, making a sterile package for your aseptic beverages.

The filling of commercially sterilized products into pre-sterilized containers in the Aseptic Fill process

The procedure of Aseptic fill is considered much more complicated than hot fill. It is also the reason why this method cannot take the crown of hot filling in the manufacturing process.

3 proper considerations for hot fill bottle manufacturing

Apart from the process and the commonly used containers of the hot filling, you should pay attention to these three related topics below so that you can gain the most effective result of the hot filling process.

Hot Fill Balance

Primarily using very high temperatures during the process, you must be aware of the temperature impacts to your beverage, such as taste, color, flavor and even the content of vitamins and minerals.

What’s the good news?

The only way to control this situation is harmony balancing the temperature and the length of time when exposing the drink container to the heat. After that, the cooling process should occur as fast as possible after the hot filling.

Hot Fill Monitoring

Another essential factor that influences the hot filling process is the constant monitoring of the temperature. When the temperature changes, even a little bit, it will lead to many chances for the harmful microorganisms to develop and damage your beverage.

To avoid this situation, you need to equip a recirculation system to control the temperature and manage the process for you.

Hot Fill Bottling Costs

Balancing the bottling cost and quality to gain the best result

The hot-fill process requires a long chain of heating and cooling in a row. This cycle can be expensive and put a heavy burden on the financial statement of your beverage company. Besides, bottling is a difficulty for keeping the quality of your drinks, saving cost, and being fit with your beverage types.
Do not put the price of bottles overweighs its impacts on your drinks.

Conclusion

Nowadays, the progress of the beverage industry causes many advanced technologies with the optimal solution for cost and effectiveness. Hot filing is a method that the manufacturers and on-trend prefer to protect your drink quality and increase the beverage shelf life.

Running a business in this industry is a significant disadvantage for you when you lack knowledge about this process. This article has clarified the background of the hot fill process, including how it works, its outstanding features, and other related information. I hope that it helps you.

Tan Do is a global beverage ODM/OEM manufacturer and supplier located in Vietnam. Since 1996, we have built trust and credibility not only throughout Vietnam but also in many parts of the world. Leveraging state-of-the-art technology, we have crafted thousands of products that align with ISO, HACCP, HALAL, FDA, and many other standards.