The Role of Glass Packaging in the Food & Beverage Industry

Glass packaging is highly important in the food and beverage industry, without it, many of the products would not be able to reach consumers. In fact, glass has been used as a packaging material for over 3000 years. Today, as environmental awareness grows, and the importance of sustainability becomes more apparent, people prefer glass packaging more.

Glass jar packaging solutions have been used to store food and beverages for thousands of years for several reasons. The most important of them is its ability to preserve products for long periods without spoilage. Glass is inert, meaning there is no interaction or transfer between the packaging and the product. Therefore, the taste, aroma, and nutritional properties of the foods remain unchanged. Glass bottle packaging also looks premium with the added advantage of providing food safety.

Accordingly, the roles of glass packaging in the food and beverages industry are as follows:

• Glass helps to preserve the taste and nutritional value of food and beverages. It also helps preserve the aroma and carbonation of beverages. This makes glass packaging appropriate for long-term food and beverage preservation.
• Glass doesn't contain substances such as Bisphenol A (BPA) and phthalates, which can leach into food or beverages and pose risks to human health, especially to the hormonal system.
• Glass remains non-toxic and sterile at very low or high temperatures. This makes it safe to use as food and beverage packaging material.
• Glass has long been the preferred material for preserving food. It is suitable for both short- and long-term preservation at room temperature or under refrigeration.

When its 100% recyclability is added to the listed advantages of glass, the question of “Why is glass a good material for food packaging?” becomes easier to answer.

Glass is an amorphous material with a hard, transparent and chemically resistant brittle structure. In other words, although it is solid, its molecular arrangement is irregular, similar to liquids. This makes glass transparent, and at high temperatures it can be melted and shaped easily. The main raw material of glass is silicon dioxide (SiO₂), also known as silica sand. High-purity sand, free from impurities, is used in glass production. However, when glass is produced by melting only silica sand, the resulting glass is very brittle, and its melting temperature exceeds 1600°C. Therefore, to both increase its durability and lower the melting temperature, another substance with a lower melting point, such as soda ash, is added to the silica sand.

Also, other materials like calcite and dolomite are added to the mixture of silica sand and soda to improve the glass's durability. The mixture, known as the batch, then melted at high temperatures.

Molten glass moves through channels (the forehearth) and reaches the forming machines. There, it is cut into set amounts, known as gobs, and directed into molds. Two forming methods are mainly used, blow and blow and press and blow. The blow and blow technique is generally used for narrow neck beverage glass bottles, while the press and blow are used for jars and similar products. In the first stage, a preform is created, then it moves to a second mold where it takes its final shape.

Once formed, it goes through a process called annealing. During annealing, the glass is heated and cooled at controlled intervals to remove internal stress and increase the durability. In the final cold end stage, the products pass through an inspection and finishing step. A surface coating may be applied to reduce friction and improve resistance. Each glass packaging design is checked by automated systems, and suitable ones are then packed and made ready for shipment.

Taste is one of the most important factors, if not the most important, in the process of purchasing food and drink. Under specific conditions, such as exposure to oxygen, humidity, light, smell and heat, as well as microbiological, biological, chemical and physical factors, food can degrade. For that matter, most of the food and beverage producers firstly consider the material when selecting packaging.

The raw materials used in the food and drink industry should be non-reactive, namely, they should not interact with food or drink. At this point, glass, with its natural characteristics, has a special position in food packaging. Glass food jars and bottles are inert and impermeable, thus protecting food from external factors. Besides, glass is a non-reactive material with no migration between the glass jar packaging and its inside. Therefore, it preserves the taste or flavour of food.

Glass packaging solutions are widely used in the food and beverage industry for fruit juices, canned fruit and vegetables, mineral water, carbonated drinks, alcoholic and non-alcoholic beverages, and milk and dairy products. There are many different packaging materials for milk and dairy products, however, beverage glass bottles have special significance for preserving taste and quality, and for consumer perception. In dairy glass packaging products, packaging needs to protect the product without affecting its structure or composition. Glass has a strong position thanks to its inert, non-porous and impermeable nature.

Glass bottles do not interact with milk, helping preserve its taste, purity and quality. They also support temperature stability while preserving the flavor and quality. Glass bottles are suitable for reuse as collection, cleaning and reuse is possible. Therefore, glass packaging not only protects products, but also makes more sustainable use of resources in dairy industries possible.

In processed foods, the role of packaging materials is to protect the product and prevent any change in its properties. Glass is impermeable so it does not allow the passage of water vapor or gases, regulating the product's moisture content. Therefore, it supports a longer shelf life, especially for jams, pickles, sauces, and canned fruits and vegetables. Glass food jars are also easy to fill, seal and use, making them suitable for processing foods.

Major global problems such as climate change, population growth, the accelerated depletion of resources, and air pollution, nowadays, lead people to think more about the environment and take steps to reduce their impact. This, in turn, makes sustainability an important part of life. Sustainability, in the most general sense, is the ability to meet the needs of today without compromising the ability to meet the needs of future generations.

The role of glass packaging in food packaging is not only to protect the taste, aroma and quality of food, but it also serves sustainability. Because glass is 100% recyclable without any loss of quality. Using sustainable glass packaging reduces the need for natural resources such as sand, soda ash and limestone. As a matter of fact, recycling one ton of glass saves over one ton of natural resources.

Food contact materials (FCMs) can affect their taste and smell, and in some cases also pose risks to human health. For this reason, food grade glass containers go through a series of quality control checks before reaching consumers. According to the Turkish Food Codex Regulation on Food Contact Materials and Articles which are Intended to Come into Contact with Foodstuffs, glass packaging should resist sudden temperature change of at least 42°C. In addition, resistance to internal pressure should fall within defined limits depending on the product. For example, pressure resistance is generally around 10-12 kg/cm² for alcoholic beverages and 10-16 kg/cm² for soft drink bottles.

Compatibility with the filling process is another factor that shapes the performance of food containers glass packaging. In products such as jams and canned foods, where hot filling is necessary, a certain amount of headspace is left inside the jar or bottle. This space usually does not exceed 10% of the container’s capacity and helps limit the risk of spoilage by allowing a partial vacuum to form as the product cools. At the same time, the dimensional accuracy of glass containers is regularly checked. Measurements such as height, diameter, and the finish of the neck should align with standards so that closures fit properly and the containers move smoothly along filling lines.

In the final stage, a careful check is carried out on the glass containers for visible defects. If they have cracks, chips or bubbles, they can pose a risk to product safety, so are not used. Before filling, cleaning and checking each container for contamination is also necessary. It is even more important when the containers are reused, since residue or foreign substances can't be in contact with the product.

As Şişecam, we produce various solutions. Our packaging range extends from 6 cc to 15000 cc with options to suit a variety of products and production needs. In the beverage sector, we support both alcoholic and non-alcoholic categories. On the food side, the range of jars and bottles available can help improve manufacturing processes.