Freeze-drying food is a common technique used to preserve the nutritional value of food and extend its shelf life. While this method is quite effective, you must be deliberate in the storage process to ensure you reap these benefits. This article will guide you on the right steps to follow when storing freeze-dried food.
How to Store Freeze-dried Food
Freeze-drying is a special kind of dehydration technique. In this process, water in the form of ice is removed from food through sublimation. It takes place in three phases; first, freezing of the food, then following the primary and secondary drying process. Storage is then done after this process is complete.
Food storage should be done systematically, following several steps. This is recommended to ensure you do not fail to do something critical. In this section, we will learn what is done in these steps.
Choose High-quality Freeze-dried Food
Freeze-dried food can be stored for up to 25 years. However, for the food to last this long without getting bad, it has to have undergone the proper freeze-drying technique. In other words, it has to be high-quality freeze-dried food.
Freeze-drying removes water particles starting with the outside of the food. This means that the center of the food item is the last part to be dried. Therefore, you can easily identify when the food is completely dry by checking the center of the food.
For instance, when you break the item and find ice particles, it means that the food is not completely dry. This could be the case even after the first and second drying cycles for some food items. In such cases, it is advisable to dry the food one more time for it to be completely dry.
Assemble Necessary Storage Supplies
Storing food that has not been preserved by methods such as freeze-drying is quite straightforward. This means that you do not need special equipment or storage supplies.
In this case, there are several items that you need to include in your storage supplies for your storage to be successful. Here are some common items;
- Oxygen absorbers – These are small packets filled with salt and iron powder that remove oxygen from enclosed containers.
- Desiccant packets – These packets work in the same principle as oxygen absorbers; that is, they keep moisture out of sealed environments. They are made of silica.
- Airtight containers – There are many types of containers you can use for storing freeze-dried food, but Mylar bags and mason jars are guaranteed to provide the longest shelf life.
- Labels and markers – Labeling stored food is essential to help you and others know the contents of the storage containers.
Ensure Food is Completely Dry
Moisture in food facilitates the growth of mold. Also, it can spoilage rate, which ultimately reduces the shelf life of food. This is something that you do not wish for, especially if you are planning on storing food for up to 25 years.
The only way to ensure this is by making sure that the freeze-dried food is free from moisture. This can be done by manually inspecting all the food. Also, when handling the food, ensure that the surroundings are not wet. In most cases, while the food could be dry, it may end up absorbing water from its surroundings, thereby affecting its dryness.
Pack the Food in Sizeable Portions
It is not advisable to store all the freeze-dried food in one large portion. One of the obvious reasons for this is that it will become a challenge when trying to access the food. Particularly, you will end up exposing all the stored food to non-standard conditions, which could ultimately lead to reduced shelf life.
To avoid this, you need to pack the food in separate containers that hold sizeable amounts. You can determine the appropriate size of the portion based on factors such as usage, duration of storage, and type of food stored.
Add Oxygen Absorbers in the Containers
The salt and iron powder in the oxygen absorber packets create a low-oxygen environment when put in a vacuum or enclosed chamber. This in turn creates a nitrogen environment that is favourable for food preservation.
The low-oxygen environment created by these packets inhibits the growth of anaerobic bacteria and fungi. Provided that anaerobic bacteria and fungi grow in vacuums, oxygen absorbers are a must if you want to prevent their growth. Fungi can cause food poisoning or generally accelerate the rate of food spoilage.
Add desiccant packs
Unlike oxygen absorbers, desiccant packs are designed to absorb surrounding moisture. This is in case the storage location is prone to high humidity levels.
One other difference between desiccant packs and oxygen absorbers is that the latter is not particularly added inside the food containers. This is because they are meant to absorb moisture from the surroundings. In some cases, however, they can be added to the food containers and they will serve the same purpose.
Seal the containers properly
Sealing the food containers properly is probably the most important factor that determines how well the freeze-dried food will last when stored. This is because the whole idea of storing dry food is to keep the moisture out of the food. If this moisture finds its way back into the food, bacteria, yeast, and mold start developing, thereby spoiling the food.
The aspect of properly sealing containers involves the know-how of sealing the specific container that contains the food. This means each container has specific requirements for sealing. Therefore, you need to follow the instructions that each container has. The goal is to have airtight enclosures that will keep the food free from moisture.
Label the storage containers appropriately
Labeling is a major part of the whole process of storing freeze-dried food. Without labels, it would be quite difficult to determine the content of the food before opening it, especially when opaque containers are used.
Labeling should include items such as;
- Name of the stored food
- When food was dried
- Usage specifications
- Expected date of expiry
This information is helpful for you as the person who stored it, and for anyone else that recovers the food. Therefore, you can tell that failing to label freeze-dried food can be a challenge.
Store the food in a cool, dry, and dark place
When you have gone through all the steps necessary to prep the food for storage, you now move to the final part of deciding where to store the food. Ideally, you need to have already selected the storage location beforehand to avoid the hassle.
The three major features of the storage location are that the location should be dry, cool, and shielded from direct sunlight. For cool and dry, the implications are quite straightforward. On the other hand, the location needs to be dark to avoid oxidation which affects the nutrients in food. This factor also improves other aspects such as limiting photodegradation and photooxidation.
Check the stored food regularly
Even though freeze-dried food can last years without degradation, it is recommended to regularly check on it. When storing the food, the conditions might be perfect, but over time they can deteriorate. This can negatively impact the environment, thereby leading to food spoilage.
One of the best practices when performing these routine checks is to rotate the stored food and ensure that you use old stock before the recently freeze-dried food. This ensures that the lifespan of the already preserved food is not affected.
Best Practices for Storing Freeze-dried Food
While the above section provides you with the steps that you need to follow when storing freeze-dried food, it leaves out an important component. In other words, we did not highlight some of the additional best practices that will make the whole process worthwhile.
Let us do that by looking at some of the common do’s that will guarantee a successful outcome at the end of the storage period.
Use clean containers to avoid cross-contamination
Bacteria is a major enemy of stored food. As you already know, bacteria thrive in dirty conditions. As such, keeping everything sanitary will ensure a positive outcome with the storage. Dirty containers can cause cross-contamination, which is a situation where germs or bacteria are transferred from one medium to another.
One way you can do this is by making sure that you wash containers properly with the appropriate detergent. Also, if possible, let them dry in the sun. finally, disinfect anything that is prone to contamination.
Choose storage location carefully
As we said earlier, the storage location you choose for your freeze-dried food will have a major impact on how the preservation turns out. This goes to show that you should be deliberate when choosing the storage location.
When stating the features of the storage location, one factor that we did not mention is that the location also has to have good airflow. This means that it should have ventilation which facilitates the flow of fresh air every so often. This is important to prevent the build-up of stale air which can facilitate bacterial growth and bad odors.
Monitor humidity levels
If the storage location is prone to humidity, you should keep checking to ensure that the humidity levels are sufficient. In some cases, you can also use a dehumidifier that will keep the location free from high levels of water vapor in the atmosphere.
Protect food against pests
Pests can be hazardous for stored food. For one, freeze-drying is a relatively expensive food preservation technique. Therefore, you need to avoid losses by ensuring that the food is not destroyed by pests.
Again, pests can impact you directly if they come into contact with the stored food. One way they can do this is by transferring their diseases to you if you consume food that they have contaminated. This is why you need to employ pest control measures such as setting traps and repellants to keep them off.
Learn more about freeze-dying food
Freeze-drying is quite a technical process. At face value, it might not seem like it, but what goes on at the molecular level is quite complex. If you are fairly learned, you will understand this process completely. This is important to ensure that you understand why the food suddenly becomes rigid and tasteless when dried.
Also, you need to understand this process because different foods will have different specifications for drying and storage. These aspects influence the shelf life and also the preservation of the nutritional value of the food.
Include usage instructions for others
In the second-last step of the storage process, we talked about labeling food. On top of the labels, you should also consider adding instructions for others who will have access to the food in the future.
Instructions for the food could include preparation and usage manuals. To elaborate, you can add notes on how the food was prepared or how it needed to be prepared. This will help avoid mishandling during the retrieval phase in the future. This is why labeling is an essential step in the process of storing freeze-dried food.
Modern food preservation methods such as freeze-drying still borrow a lot from traditional storage techniques as demonstrated in this article. These conditions have worked for ages but with one major shortcoming — limited shelf life. Freeze-drying on the other hand has the advantage of preserving food for up to 25 years, making it the ideal technique today.