Freeze drying is a method that can be used to remove water from foods. Freeze drying is also a method that can be used to reduce the weight of the food that is to be transported. When you pack your suitcase for a long trip, the food can become very heavy.
By using freeze drying to remove the water from the food that you will eat on the trip, the food weight will be much more lighter. While many people may purchase commercial meal that have been freeze dried, anyone can prepare freeze dried meals for themselves. By removing the water from the food that contains alot of water, the food can be made much lighter and easy to carry.
How Freeze Drying Works and Why It Helps
To remove the water from the food, a process called sublimation are used. Sublimation is the process of first freezing the food, then placing it into a vacuum chamber to lower the pressure around the food. As a result, the ice within the food will turn into a vapor without becoming liquid water.
Since the ice is turning into a vapor through the process of sublimation, the food will retain its original structure and will not shrivel. The sublimation process will remove the moisture from the food, leaving behind a porous structure in the food. This porous structure allows the food to absorb water again when its time to eat the food.
Though it is a slow process that may take over a day to complete, freeze dried food have a very long shelf life if they are stored correctly. When food is freeze dried, there will be a noticeable change in the weight of the food. For instance, a large amount of fresh spinach will produce a small amount of flake after the spinach is freeze dried.
In order to understand the weight of the food after it is freeze dried, a conversion chart may be used. The weight ratios of food will change after freeze drying, and different types of food will have different ratio. For instance, leafy vegetables will lose more weight than foods that are more dense, like beef.
Additionally, if a person does not understand the ratios of the different foods, they may prepare too little food or not enough food for themselfs during there trip. One of the main benefits of freeze drying is that the calories remains within the food after the water is removed. For instance, one ounce of freeze dried strawberries will contain a significant amount of calories.
Additionally, the freeze dried strawberries will be more efficient than fresh strawberries because the freeze dried strawberries do not contain the weight of the water that the fresh strawberries contain. The benefits of freeze drying can also be seen in foods like lean meats and cooked grains that also contain fewer calories per ounce, yet still provide the same nutritional benefit. However, not all foods are appropriate to freeze dry.
Freeze drying machines work well for foods that contain a lot of water, but do not work well for foods that contain high amounts of fat or sugar. Foods that contain high amounts of fat, like butter, will not freeze well in the freeze drying machine. Additionally, the fats in the food will go rancid within the freeze drying machine, even if the food is placed in a sealed bag.
Foods that contain high amounts of sugar, like honey, will create a sticky barrier to the vacuum created by the freeze drying machine. As a result, freeze drying these foods will create a gummy product that is not dry. Therefore, not all the food in a persons pantry should be freeze dried.
In order for the food to return to its original state, it must be rehydrated. Water can be added to the food while it is freeze dried to rehydrate it. Cold water can be used, but the process is slow.
Additionally, if the food is rehydrated with cold water only, the center of the food may remain crunchy. In order to speed up the rehydration process, you can use hot water. Hot water will cause the porous structure in the food to open, allowing the water to penetrate the food.
Additionally, hot water will rehydrate the food faster than cold water. Additionally, different foods will require different amounts of time to rehydrate. For instance, chicken will require more time to rehydrate than spinach.
To rehydrate the food quickly, you can add the freeze dried food to a simmering pot of cooking liquid. Adding freeze dried food to a simmering pot will rehydrate the food the fastest. In order to store the freeze dried food, the food must be stored in a way that will ensure that it remains edible for as long as possible.
If freeze dried food is stored in a porous container, the freeze dried food will absorb the moisture from the air, causing it to spoil. To prevent this from occurring, the food should be stored in airtight Mylar bags and oxygen absorber. Using Mylar bags and oxygen absorbers will allow the freeze dried food to retain its quality over time.
Additionally, the freeze dried food should be stored in a cool location. A cool pantry will preserve the food for a long time, but a hot garage will cause the freeze dried food to spoil much more faster. Proper storage will allow the freeze dried food to remain edible for many years.
