Never again freezer burn: How to freeze food correctly
Freezing food: A key to preventing waste and promoting sustainable food storage.
In a time when around a third of all food produced worldwide is thrown away, the issue of food waste is becoming increasingly important. Even in private households, tons of edible food end up in the trash every year – often due to ignorance, lack of time, or poor planning. However, there are simple and effective methods to counteract this. One of them is the targeted freezing of food.
Freezing not only extends the shelf life of food but also allows for better organization in everyday life: Cooked leftovers don't have to be thrown away, fresh fruits and vegetables can be bought seasonally and preserved, and spontaneous meals are always readily available. Those who consciously freeze food save money, reduce waste, and actively contribute to climate protection.
But for freezing to be truly sensible and sustainable, the right packaging is crucial. Not every material protects food equally well from freezer burn , loss of flavor , or the migration of harmful substances . At the same time, environmental compatibility is playing an increasingly important role: petroleum-based single-use plastics, aluminum, and other conventional packaging strain resources and leave their mark – often in the form of microplastics or CO₂ emissions.
In this article, we take a close look at the various packaging materials for freezing , compare their advantages and disadvantages, and show how to store food safely, practically, and in an environmentally friendly way . Finally, we present a natural alternative that combines functionality and sustainability.
Packaging & materials for freezing in detail
When freezing food, the choice of packaging is crucial for shelf life, quality, and sustainability. Here's a detailed look at the most common materials:
Plastic/petroleum-based freezer bags
Plastic freezer bags made of polyethylene (PE) or polyethylene terephthalate (PET) are the most common solution. They are lightweight, flexible, and can be sealed airtight – ideal for space-saving freezing. However, they are petroleum-based and not biodegradable. Microplastic particles can be released under mechanical stress or prolonged storage. Furthermore, some plastics contain additives that can leach into food under certain conditions.
Typical application: Vegetables, bread, meat, flat portions
Sustainability: low, mostly disposable, petroleum-based
Plastic boxes
Plastic boxes made of polypropylene (PP) or polyethylene (PE) are more stable and reusable. They offer better protection against freezer burn and are often dishwasher-safe. However, they are also petroleum-based and not biodegradable.
TTypical application: Freezing soups, stews, cut vegetables or prepared meals
Sustainability: Reusable, easy to clean, but petroleum-based
Glass
Glass containers are a non-toxic and durable alternative. They are particularly suitable for solid foods such as casseroles, soups, or fruit. It is important to use only freezer-safe glass and to allow sufficient space for liquids to expand. Glass is odorless and easy to clean, but it is heavy and fragile.
Typical application: Soups, stews, pieces of fruit
Sustainability: High, as it is reusable, but high energy consumption during production.
Stainless Steel
Stainless steel containers are robust, hygienic, and durable. They don't leach any substances into food and are ideal for plastic-free freezing. However, they are not transparent, which makes it difficult to see what's in the freezer. Without a special seal, they aren't always airtight, which can promote freezer burn.
Typical application: prepared meals, pastries
Sustainability: very high, durable and recyclable
Silicone Sealant
Silicone bags and molds are flexible, reusable, and particularly suitable for liquids or small portions. They are dishwasher-safe and space-saving. However, silicone is not biodegradable, and its production is energy-intensive. In cheaper products, plasticizers or fillers may leach out.
Typical application: Smoothies, broth, baby food
Sustainability: medium, depending on quality and origin
aluminum foil
Aluminum foil provides a good barrier against air and moisture and is malleable. It is suitable for the short-term freezing of small quantities. However, its production is very resource-intensive (bauxite mining) and aluminum can leach into acidic foods upon contact. Furthermore, aluminum foil is usually single-use and difficult to recycle.
Typical application: Herbs, small portions, baked goods
Sustainability: low energy consumption, disposable product, high energy demand during production
Bags/films made of bioplastic
In addition to PLA-based bioplastics, there are also freezer bags made from starch, which are produced using corn or potato starch. These bags are biodegradable and compostable, often certified according to EN 13432. They offer a petroleum-plastic-free freezing option, but are not always as temperature-resistant or tear-resistant as conventional materials.
Typical application: Freezing vegetables, bread, fruit, baked goods
Sustainability: renewable raw materials, pollutant-free, compostable, microplastic-free
Comparison table: Materials for freezing food
| Material | Benefits | Disadvantages | Sustainability |
| Plastic bags (petroleum-based) | Flexible, airtight, affordable | Petroleum-based, microplastics, unsustainable | Not sustainable, based on petroleum |
| Plastic boxes (petroleum-based) | Reusable, durable, dishwasher safe | Petroleum-based, not biodegradable | Long-lasting, but fossil-based |
| Glass | Free of harmful substances, durable, odorless | Heavy, fragile, not necessarily suitable for liquids | Reusable, but energy-intensive |
| Stainless Steel | Robust, reusable, hygienic | Expensive, opaque, airtight only with a seal | Very durable, resource-efficient |
| Silicone Sealant | Reusable, flexible, dishwasher safe | Not biodegradable, quality differences | Reusable, but not compostable |
| aluminum foil | Good barrier, malleable | Resource-intensive, unsustainable | Disposable product, high energy consumption |
| Biodegradable bags/cornstarch bags | Compostable, made from plants | Not heat resistant | Bio-based, microplastic-free, compostable |
How to freeze food sustainably: What should you pay attention to?
- Portioning: Small quantities thaw faster and avoid waste.
- Label: The date and content help with the overview.
- Pack airtight: Prevents freezer burn and loss of aroma.
- Store in a space-saving way: Use flat bags or stackable containers.
- Prefer reusable alternatives: Glass, stainless steel or bioplastic instead of single-use plastic.
Conclusion: Freezing food consciously – with the right equipment
Whether glass, stainless steel, silicone, or bioplastic – every type of packaging has its strengths and weaknesses. Those who want to freeze food safely and sustainably should opt for reusable or biodegradable materials. The NaKu Bio freezer bag offers an environmentally friendly alternative that combines functionality and sustainability. It is available in various sizes and pack sizes in our online shop.
FAQ – Frequently Asked Questions about Freezing Food
Which material is best suited for freezing food?
It depends on the intended use. Glass and stainless steel are particularly durable and free of harmful substances, while plastic boxes are practical and widely used. Bioplastics offer a sustainable solution.
What is the difference between freezer bags and plastic boxes?
Freezer bags are flexible and usually intended for single use. Plastic containers are more stable, reusable, and better suited for liquids or prepared foods.
Can I freeze glass containers without any problems?
Yes, but only special freezer glasses. Normal glass can crack due to temperature fluctuations – especially with liquids that expand when freezing.
How do I avoid freezer burn?
Airtight packaging, rapid freezing, and avoiding temperature fluctuations are helpful. Materials with good barrier properties, such as stainless steel, glass, or airtight plastic boxes, are beneficial.
Are silicone bags a good alternative to plastic?
Yes, they are flexible, reusable, and ideal for liquids. However, they are not biodegradable and their production is energy-intensive.
How sustainable are plastic boxes really?
Their sustainability depends on their lifespan. If used for years, they are better than disposable products, but they remain fossil-based and not biodegradable.
What is special about the NaKu Bio freezer bag?
It is made from bioplastic based on renewable raw materials, is compostable, food-safe, and free of microplastics. A natural alternative to conventional freezer bags.
Can I use aluminum foil for freezing?
Yes, but with caution. It offers good barrier properties, but is ecologically questionable and can transfer aluminum when used with acidic foods.
Which foods are particularly suitable for freezing?
Vegetables, fruit, bread, meat, fish, soups, and prepared meals. Proper portioning and packaging are essential.
What's the best way to label frozen food?
Include the date and contents – either directly on the container or with labels. This helps you keep track and avoids unnecessary waste.
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