Food Preservation: What It Is, Why It Matters & How to Do It Right

by Joost Nusselder | Last Updated:  May 27, 2022

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Food preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), or other micro-organisms (although some methods work by introducing benign bacteria or fungi to the food), as well as retarding the oxidation of fats that cause rancidity.

Food preservation is a way to keep food from spoiling or going bad. It’s been practiced since ancient times and there are many different ways to preserve food. From drying to canning, there’s a method for every food.

In this article, I’ll explain what food preservation is, how it works, and why it’s so important in our lives today. Plus, I’ll share some fun facts along the way.

What is food preservation

In this post we'll cover:

Preserving Food: A Key Practice for a Longer Food Supply

Food preservation is the process of maintaining the quality and safety of food products by applying different methods and techniques. The goal of food preservation is to prevent the growth of microorganisms, slow down the oxidation of fats, and protect the food from unwanted changes in texture, flavor, and color. This practice has a long and rich history, with evidence of ancient civilizations using various methods to preserve food for routine use.

What Methods are Included in Food Preservation?

Food preservation includes a wide range of techniques that can be applied depending on the type of food and desired outcome. Some commonly used methods include:

  • Drying: removing water from the food product to prevent the growth of microorganisms
  • Freezing: lowering the temperature to slow down the oxidation process
  • Canning: sealing food in containers and heating to destroy any potential harmful elements
  • Fermentation: using active compounds to produce a unique flavor and increase shelf life
  • Chemical preservation: using ingredients to prevent the growth of microorganisms

What are Some Examples of Food Preservation Techniques?

Food preservation techniques have been developed and built upon over the past centuries, with some prominent examples including:

  • Ancient civilizations drying and salting fish and meat to preserve them for routine use
  • Native Americans smoking meat to preserve it for long periods of time
  • Vietnamese cuisine using pickling and fermentation to produce unique flavors and increase shelf life
  • Chinese cuisine using rice to absorb excess moisture and prevent spoilage in food products

How Can Understanding Food Preservation Benefit Us?

Understanding food preservation can help us make informed choices about the food we consume and how we store it. By knowing the different methods and techniques available, we can properly preserve our food products and reduce food waste. Additionally, understanding the potential risks and affecting factors can help us address any issues that may arise during the preservation process. Food preservation is an important practice that contributes to a longer food supply and the availability of fresh produce year-round.

From Farm to Table: Traditional and Modern Methods of Food Preservation

  • Drying: One of the oldest methods of food preservation, drying involves removing water from the food product to prevent the growth of mold and bacteria. This method is commonly used for fruits, vegetables, and meat.
  • Fermentation: This method involves the use of microorganisms to break down the sugars in food, producing lactic acid and other compounds that prevent the growth of harmful bacteria. Examples include sauerkraut, kimchi, and yogurt.
  • Smoking: This method involves exposing food to smoke from burning wood or other materials, which can add flavor and help preserve the food. Examples include smoked meat and fish.
  • Ash and Rice: In some parts of the world, ash and rice are used to preserve food. Ash is used to control the pH of the food, while rice is used to absorb moisture and prevent the growth of mold.

Modern Industrial Techniques

  • Freezing: This method involves lowering the temperature of the food product to below freezing, which slows down the growth of bacteria and other microorganisms. This method is commonly used for meat, vegetables, and other perishable foods.
  • Canning: This method involves heating food to a high temperature to kill bacteria, then sealing it in cans or other containers. This method is commonly used for fruits, vegetables, and soups.
  • Pasteurization: This method involves heating food to a high temperature for a short period of time to kill bacteria and other microorganisms. This method is commonly used for milk and other dairy products.
  • Irradiation: This method involves exposing food to ionizing radiation to kill bacteria and other microorganisms. This method is commonly used for spices, fruits, and vegetables.
  • Adding Chemicals: This method involves adding chemicals to food to prevent the growth of bacteria and other microorganisms. Examples include salt, vinegar, and citric acid.

Comparison of Traditional and Modern Techniques

  • Energy Input: Traditional methods require little to no energy input, while modern methods require a significant amount of energy.
  • Quality: Traditional methods are known for producing high-quality, natural products, while modern methods can sometimes result in a loss of flavor and texture.
  • Control: Modern methods allow for greater control over the preservation process, while traditional methods are more dependent on environmental factors.
  • Expertise: Traditional methods require a certain level of expertise and knowledge, while modern methods can be applied by anyone with the proper equipment.
  • Storage: Traditional methods often require cool, dry storage conditions, while modern methods allow for more flexible storage options.
  • Biological Action: Traditional methods rely on the biological action of mold and bacteria to preserve food, while modern methods rely on multiple steps and processes to achieve the same result.

Overall, both traditional and modern methods of food preservation have their advantages and disadvantages. While traditional methods are often seen as more natural and produce higher-quality products, modern methods allow for greater control and can effectively prevent the growth of harmful bacteria.

Preserving Food with Chemicals: Understanding the Science Behind It

Preserving food with chemicals is a scientific process that involves the use of various materials to prevent the growth of unwanted organisms and slow down oxidation. These chemicals are commonly referred to as preservatives and are classified into two main classes: natural and synthetic.

Natural Preservatives

Natural preservatives are compounds that are found in nature and can help preserve food. Some of the most commonly used natural preservatives include:

  • Salt: Salt is a commonly used preservative that helps to control the growth of bacteria and mold. It can be used in both water and dry preparations.
  • Vinegar: Vinegar is a helpful preservative that supports the preservation of a wide variety of foods. It is commonly used to preserve vegetables and fruits.
  • Alcohol: Alcohol is a preservative that is commonly used to preserve a range of products, including fruits, vegetables, and high moisture foods.

Synthetic Preservatives

Synthetic preservatives are chemicals that are added to food to inhibit the activity of microorganisms and reduce moisture to decrease the speed of spoilage. Some of the most commonly used synthetic preservatives include:

  • Sodium benzoate: Sodium benzoate is a preservative that is commonly used to inhibit the growth of bacteria and fungi. It is frequently used in soft drinks, fruit juices, and syrups.
  • Sulphur dioxide: Sulphur dioxide is a preservative that is commonly used to preserve dried fruits and vegetables. It helps to kill bacteria and inhibit the growth of molds.
  • Sorbic acid: Sorbic acid is a preservative that is commonly used to preserve a wide range of foods, including cheese, baked goods, and high moisture foods.

The Benefits of Preservatives

Preservatives are helpful in preserving food and extending its shelf life. They can also aid in the prevention of foodborne illnesses caused by bacteria and other microorganisms. Proper understanding and use of preservatives can help to ensure that food is prepared and preserved according to the required level of safety.

The Different Techniques Used in Preserving Food with Chemicals

There are a lot of different techniques used in preserving food with chemicals. Some of the most common techniques include:

  • Inhibiting the growth of microorganisms: Preservatives such as sodium benzoate and sorbic acid are commonly used to inhibit the growth of bacteria and fungi.
  • Reducing moisture: Preservatives such as sulphur dioxide and calcium propionate are commonly used to reduce moisture and slow down the growth of microorganisms.
  • Decreasing the speed of oxidation: Preservatives such as butylated hydroxy toluene (BHT) and tert-butylhydroquinone (TBHQ) are commonly used to decrease the speed of oxidation and prevent spoilage.

Frequently Asked Questions

  • What is the difference between natural and synthetic preservatives?
  • Are preservatives safe to consume?
  • What are the most commonly used preservatives?
  • How do preservatives work to preserve food?
  • Can preservatives cause adverse reactions in some people?

The Importance of Understanding the Main Goal of Food Preservation Methods

The primary goal of any food preservation method is to prevent food spoilage until it can be consumed. This serves to protect the food supply and contributes to overall food security. Food preservation methods are designed to improve the shelf life of food products and allow for a wide variety of foods to be available year-round.

What factors affect the preservation of food?

Several factors can affect the preservation of food, including:

  • The type of food being preserved
  • The method of preservation used
  • The internal water content of the food
  • The presence of active compounds in the food that can cause spoilage
  • The cleanliness of the kitchen and processing area
  • The storage conditions of the final product

What are some common mistakes when preserving food?

Despite the long history and routine practice of food preservation, there are still some common mistakes that can affect the final product. These include:

  • Not properly cleaning and sanitizing equipment and work surfaces
  • Not following the correct processing times and temperatures for canning
  • Not properly storing canned or dried foods in a cool, dry place
  • Using low-acid foods in a water-bath canner instead of a pressure canner, which can result in botulism
  • Not fully understanding the potential biological changes that can occur during the preservation process

What are some key ingredients and compounds used in food preservation?

Several key ingredients and compounds are used in food preservation, including:

  • Salt: Used to draw out moisture and prevent spoilage
  • Vinegar: Used in pickling to lower the pH and prevent bacterial growth
  • Sugar: Used in jams and jellies to create a high-sugar environment that inhibits bacterial growth
  • Nitrites and nitrates: Used in curing meats to prevent bacterial growth and improve flavor
  • Sulfites: Used in dried fruits and wines to prevent browning and spoilage

What are some modern methods of food preservation?

In addition to the ancient methods of food preservation, there are also modern methods that have become popular in recent years. These include:

  • High-pressure processing: This involves using high pressure to kill bacteria and extend shelf life.
  • Modified atmosphere packaging: This involves changing the atmosphere around the food to slow down spoilage.
  • Irradiation: This involves exposing foods to ionizing radiation to kill bacteria and extend shelf life.

Despite the availability of these modern methods, traditional methods of food preservation are still widely used and offer unique benefits depending on the type of food being preserved.

Factors That Affect Food Preservation

Water is a key element in food preservation. The water content in food affects the preservation method that can be applied. Some preservation methods require the removal of excess water, while others require the presence of water. Examples of preservation methods that require water include canning, freezing, and drying.


Temperature is another important factor affecting food preservation. The majority of preservation methods require a low temperature to prevent the growth of bacteria and other biological agents that can cause food spoilage. However, some preservation methods, such as cooking, require high temperatures to destroy harmful bacteria.


The pH level of food is another factor affecting preservation. Foods with a high acidity level, such as pickles and sauerkraut, can be preserved for a longer time compared to foods with a low acidity level.

Redox Potential

The redox potential (Eh) of food refers to the presence of oxidizing and reducing agents. This factor affects the final product of food preservation.

Methods of Preservation

There are a wide variety of preservation methods available, each designed to address specific factors affecting food preservation. Some commonly used methods include canning, freezing, drying, and the use of preservatives.

Types of Foods

Different types of foods require different preservation methods. For example, fruits and vegetables are often dried or canned, while meat products are commonly frozen or cured.

Containers and Cleaning

The type of container used to store preserved foods can significantly affect the preservation process. Clean containers are necessary to prevent the growth of bacteria and other microorganisms.

Common Mistakes to Avoid When Preserving Food

One of the most common mistakes when preserving food is not properly cleaning and handling the materials used in the process. This can result in the presence of biological contaminants that can affect the final product’s safety and quality. To avoid this, it is essential to follow proper cleaning and handling procedures, including inspecting containers for cracks or damage, washing hands thoroughly before handling food, and using clean utensils and equipment.

Not Following Proper Preservation Methods

Different types of foods require different preservation methods, and not following the correct method can significantly affect the final product’s quality and safety. For example, drying is a widely used method for preserving produce, but it may not be suitable for all types of foods. Some foods may require freezing or canning to prevent spoilage and maintain their freshness. It is essential to understand the unique preservation needs of each food type and follow the correct method to achieve the desired goal.

Ignoring the Importance of Consistent Processing

Consistency is key when it comes to food preservation. Failure to maintain consistent processing can result in changes in the product’s content, affecting its quality and safety. For example, excess water in canned products can cause spoilage, while insufficient drying can lead to the growth of bacteria and mold. It is essential to follow a routine and maintain consistency in the preservation process to ensure the final product’s safety and quality.

Not Paying Attention to Storage and Dates

Proper storage and labeling are crucial when it comes to preserving food. Failure to store products correctly or label them with the correct dates can result in spoilage and potential health risks. It is essential to store preserved products in clean, airtight containers and label them with the date of production. Remember to inspect the products regularly and discard any that show signs of spoilage or damage.

Using Chemicals Incorrectly

While chemicals can be used to improve the quality and shelf life of preserved foods, they must be used correctly. Using too much or too little of a particular chemical can result in the product’s spoilage or cause other health risks. It is essential to follow the instructions carefully and use only the recommended amount of chemicals to achieve the desired result.

Frequently Asked Questions About Food Preservation

Natural methods of food preservation involve hindering the growth of unwanted organisms through processes like heating, decreasing the pH, or protecting the food with organic ingredients like acetic acid in vinegar. Chemical methods of food preservation include compounds like sodium nitrate or sodium benzoate that target specific microorganisms and prevent spoilage. While natural methods are generally considered safer, they may not be as effective at extending the shelf life of foods as chemical methods.

What is the best method for preserving food in the freezer?

The best method for preserving food in the freezer involves removing as much air as possible from the packaging to prevent freezer burn. This can be done by using a vacuum sealer or by wrapping the food tightly in plastic wrap. It’s also important to label the food with the date it was frozen and to use it within a reasonable amount of time.

What is the aim of preserving food through canning?

The aim of canning is to preserve food by removing air from the container and creating a vacuum seal that prevents the growth of microorganisms. This involves heating the food to a high temperature to kill any bacteria or spores that may be present and then sealing it in a can or jar. The goal is to create a shelf-stable product that can be stored for long periods of time without spoiling.

What is the role of salt in preserving food?

Salt is a notable ingredient in many preservation methods as it hinders the growth of microorganisms by drawing water out of their cells. This decreases the water activity in the food, making it less hospitable to bacteria and other organisms that cause spoilage. Salt can be used in curing, smoking, and pickling, among other methods.

What is the difference between preserving and processing food?

Preserving food aims to retain the nutritional value of the food while hindering the growth of microorganisms that cause spoilage. Processing food, on the other hand, involves changing the food in some way, such as cooking or baking, to make it more palatable or to create a new product. While preserving and processing can involve similar techniques, the end goals are different.


So, food preservation is a way to keep food longer and prevent it from going bad. There are many different methods, but the most common are drying, freezing, canning, and fermentation. 

So, now you know how to preserve food and you can use this knowledge to keep your food supply fresh and ready to eat.

Joost Nusselder, the founder of Lakeside Smokers is a content marketer, dad and loves trying out new food with BBQ Smoking (& Japanese food!) at the heart of his passion, and together with his team he's been creating in-depth blog articles since 2016 to help loyal readers with recipes and cooking tips.