Freeze Dried Food Vs Dehydrated,What is the Difference Between Them?

Freeze Dried Food Vs Dehydrated Many people think of dehydration and freeze-drying as the same thing. They are not. They are very different from each other.

The following explains the differences between these two food preservation techniques.

Dehydration Process

Regardless of the type of food preservation used, water needs to be removed. Dehydration is the most common of these methods.

Dehydration is a food preservation method used for thousands of years, dating back to at least 12,000 BCE. The Romans and Middle Easterners used to put fruits and vegetables in a house and then roast and smoke them to make dry food.

Modern dehydration techniques have become simple, using machines to circulate hot and cold air through food. This removes most of the moisture. The temperature is controlled to a level sufficient to remove the moisture but not to cook the food. The dehydrated food wilts and hardens.

Dehydrated food is food that has had most of its water content removed through a drying process, typically through the use of low-heat or air-drying techniques. This process makes the food lighter, more compact, and less perishable, which makes it an ideal option for long-term storage, camping, hiking, and emergency preparedness kits.

Dehydrated food can be made from various fruits, vegetables, meats, and grains. Some common examples include dried fruits such as raisins and apricots, beef jerky, and powdered milk. Dehydrated foods can also be purchased in bulk or pre-packaged form for convenience.

Dehydrated food is best used when fresh food is not readily available or long-term storage is required.

For example, hikers and backpackers often rely on dehydrated food for sustenance during extended trips because it is lightweight and easy to carry. Similarly, individuals who live in areas prone to natural disasters may stockpile dehydrated food as part of their emergency preparedness plan.

Additionally, dehydrated food can be a convenient option for people who want to have a healthy snack on hand without worrying about spoilage or refrigeration.

Freeze-Drying Process

Freeze-drying is a relatively new modern preservation process. It was invented during World War II when it was used to preserve blood plasma, drugs, and later troop food.

The freeze-drying process is relatively simple. Food is placed on a large shelf in a vacuum chamber. The temperature is lowered to below freezing and then gradually increased. The water in the food is converted from a solid form to a gas, thus preserving the structure and nutritional value of the food.

Freeze-dried food is a type of food that has been dehydrated using a process called lyophilization. This process involves freezing the food and placing it in a vacuum chamber where the ice crystals are sublimated, meaning they go directly from a solid to a gas state without passing through the liquid phase. This results in a dry, lightweight product with a longer shelf life than traditional dehydrated food.

Freeze-dried food is a popular choice for camping, backpacking, and emergency preparedness, as it is lightweight, easy to transport, and has a long shelf life.

It is also commonly used by astronauts and space agencies as it is an efficient way to provide food for space missions.

Freeze-dried food can be made from various ingredients, including fruits, vegetables, meats, and even full meals. Some common examples include freeze-dried fruit snacks, instant coffee, and freeze-dried entrees such as pasta dishes or soups.

Freeze-dried food is best used when long-term storage and portability are important factors. It can benefit people who enjoy outdoor activities such as hiking, camping, or backpacking, as it is easy to carry and prepare.

It is also a popular choice for emergency preparedness, as it can be stored for long periods without spoiling and can provide a quick and easy source of nutrition during a natural disaster or other emergencies.

Difference Between Freeze-Dried and Dehydrated


The main goal of food preservation is to remove water so that food does not spoil and grow mold. Dehydration removes 90-95% of the water, while freeze-drying removes 98099%.

Dehydrating food at home usually leaves 10% moisture, but professional techniques dehydrate more thoroughly, providing a longer shelf life.

Shelf life

Moisture removal rate directly affects shelf life. Dehydrated foods such as dried fruits, vegetables, and powders have a shelf life of approximately 15-20 years; dehydrated foods such as honey, sugar, salt, durum wheat, and oats have a shelf life of 30+ years. On the other hand, frozen, dehydrated foods have a much longer shelf life, such as dried fruits and vegetables can last 25-30 years.

Nutritional Composition

An American Institutes of Health study states freeze-drying retains most vitamins and minerals. However, freeze-dried foods lack vitamins, such as vitamin C, compared to fresh fruits and vegetables, which break down more quickly.

Dehydration does not alter food fiber or iron content. However, dehydration breaks down vitamins and minerals during preservation, so the nutritional value is not as good as freeze-dried foods. Dehydration tends to cause loss of vitamins A and C, niacin, riboflavin, and thiamin.

Appearance and Structure

One of the main differences between dehydrated and freeze-dried foods is their appearance. Dehydrated foods become crisp and hard, while freeze-dehydrated foods soften immediately in the mouth.

Weight is another difference. Freeze-dried foods weigh much less than dehydrated foods.


Dehydrated foods need to be cooked and eaten. Many times, they also need to be seasoned. This means cooking the product in hot water, cooling it, and serving it. It takes between 15 minutes and 4 hours to prepare dehydrated foods. Freeze-dried foods, however, only require boiling water. Add hot or cold water and wait at least 5 minutes before eating.


Overall, dehydrated foods are cheaper than cold-dried foods. There are pros and cons to freeze-dried and dehydrated foods; if you are on a tight budget, dehydrated foods are the better choice.

  • Emma Johnson

    Hello, I'm Emma Johnson. I'm embracing the joys of culinary excellence and household wizardry, infusing creativity and expertise into every aspect of the kitchen and home. With a seasoned background shaped by years of experience and various roles, my culinary journey has evolved into a testament to my expertise in the kitchen. From professional kitchens to creating warm, familial atmospheres, I bring a wealth of knowledge to make your cooking and homemaking experiences delightful. Beyond the realm of recipes and homemaking, you'll find me cherishing the company of my furry companions, exploring creative hobbies, and delighting in the simple pleasure of savoring a cozy cup of tea.

Scroll to Top