How to Dehydrate Foods for Long Term Storage
Dehydrating food has become a necessity, if you want to store food items for the long term. Preservation is the easiest and most affordable way to preserve the flavor of foods.
So, how do you go about dehydrating food for long term storage? The key is to remove moisture from the food so mold, bacterial growth and yeast cannot thrive. Dehydration should also be carried out to ensure that the nutritional content of food is preserved. This enhances its longevity too.
Estimates show that dehydrating food results in nutritional and freshness loss of only 3 to 5 percent as opposed to a 60 to 80 percent loss due to canning. Alongside this, important nutrients and vitamins are not lost or altered in the drying process.
This includes vitamin A and C, carbohydrates, fiber, potassium, selenium, sodium and magnesium. The result? You get nutrient packed food that can be stored long term.
Dehydrating food for long term storage is not something most people think of. But it can result in shelf stable food that lasts for even 25-30 years!
How to Dehydrate Food for Long Term Storage
If you are wondering about how to dehydrate food for long term storage, the first step is the equipment you will need. This brings us to the big question: how should the food be dehydrated for long term storage?
What Kind of Dehydrator Works Best?
You need to firstly invest in a long term dehydrator with solid trays that slide in and out. While nested slotted trays are also an option, stackable, switchable trays are the most convenient.
Dry food using a dehydrator with an adjustable thermostat, for optimal results. You need a home dehydrator to dry fruits and vegetables for long term storage.
Some meats take a little more time to dry at higher temperatures to enable long term storage. The temperature at which the food is dried should be stable and of the right range.
The dehydrator should have an air flow technology that evenly distributes heat to prevent extreme dryness outside and moisture retention inside.
The basic dehydrator eliminates moisture, while advanced models come with auto shut off, digital timers and fans. They also have a great amount of space for drying.
What You Need to Do
To dehydrate food well for long term storage, the first and most important point is that you need to pick the fruits and vegetables at peak ripeness to get vitamins, nutrients and flavors.
Dehydrating fruits and veggies in season saves cost. You also need to purchase an optimal dehydrator model and opt for the right dehydrating temperature for food. Steps should be taken to control moisture content before packing and storing the food.
Prepare Food Before Dehydrating
1) Dehydrating Fruits and Vegetables
This is a critical part when it comes to preparing dried food for long term storage. Firstly, you need to wash the fruits and vegetables. Prepare a 50/50 solution of water and vinegar in which to soak the food item after rinsing the product well. This removes wax and chemicals before slicing.
If you can, opt for organic fruits and veggies if you are buying them. Fruits with a lot of juice can be frozen partly before dehydrating to ensure cutting them is easier.
Use latex or vinyl gloves while cleaning the fruits and veggies and slicing them. Another way is to wash your hands thoroughly and disinfect them so no bacteria or germs can come into contact with the food.
The cores, seeds and stems need to be removed. Peel the product for better results. Most fruits can be sliced 3mm thick and one-inch in length. The sliced fruits may change color on account of oxidation. Spray lemon juice or use an acid dip to prevent browning due to oxidation.
You have to peel fruits and vegetables and slice the food items. Then, you need to place the slices on the tray, ensuring that they do not overlap. Leave the dehydrator on for anywhere from 4-24 hours, for most models at an average temperature range of 95-160 degree C depending on nature of the food items.
Depending on the kind of food it is, it will either turn hard and crisp or leathery when done. Some items like fruits also turn brown when dried. To prevent this from happening, soak your food in acid dip before setting them out on the drying trays.
For vegetable items, you need to blanch the particular food stuff. This works just like freezing and ensures that enzymes are stopped from degrading food over time. Heat in boiled water for a few minutes and then place the vegetable in icy water to blanch it.
How to Dehydrate Food
1) Drying Time
There is a wide variance in the time taken to properly dry food. While apples in most dehydrator models take 6-8 hours, bananas take 8 to 10 hours, for example.
If you are using a dehydrator for long term food storage, you need to know how long an item needs or you can end up with moisture and mold in the food. Here’s a list of average drying times for different fruits and vegetable.
While berries can take between 10 to 24 hours (blueberries take 12-24 hours and strawberries as little as 10 to 16 hours), peaches take 10 to 12 hours. Pears require 12-16 hours of dehydrating for long term storage.
Vegetables like carrots, corn, green beans, peas and potatoes need to be blanched before dehydration to ensure nutrient value following long term storage. Tomatoes need drying of 14 to 16 hours, while most other vegetables take anywhere from 1 to 12 hours (zucchinis take 6 to 8 hours only!).
4) Meat Items
These take a longer time to dehydrate and can be done with ease at a maximum temperature of 160 degree F.
5) Temperature Control
While most fruits and vegetables dry well between 135 to 125 degree F, don’t turn the temperature up thinking high heat makes it go faster. This will create a dry, hard skin outside and lead to moisture retention inside. Raising the heat to high will also kill off enzymes and reduce the nutritional value of the food to zero.
This is one of the most important factors affecting the storage duration of dehydrated food. According to the US Department of Agriculture, with every 10.08 degree F drop in temperature, the storage life of seeds is doubled.
The inverse could also hold true. The fact remains that temperature influences the period of time for which the dehydrated food can be stored, once the drying process is over.
The weather and temperature in which the dehydrated food is dried influences storage and shelf life. Frequent temperature changes can shorten the storage life. The temperature at which dehydration takes place should therefore be constant. You should also have a cool place to store the food.
6) Moisture Factor
Another important point to consider while dehydrating foods for long term storage is that dry beans, grains, and flours contain 10 percent moisture on an average. Food should therefore be as dry as possible before being stored. Dehydrated food with even a little moisture can cause the items to spoil inside their containers.
For long term storage, for example, grains need to have moisture content of less than 10 percent. Therefore, the water content of your food once dehydration is taking place, is a key factor while drying foods for long term storage.
Some fruits like plums and apricots retain more moisture and remain sticky. These need to be dried with care at optimal temperature to last as long as items like beans which dry out completely.
The produce is dry enough when it feels leathery and can be bent without breaking into pieces. Another important trick to dehydrating produce for the long term, is to condition the dehydrated produce.
This can be done by storing it in plastic zipper bags overnight, distributing the moisture in an even way and eliminating damp spots.
7) Atmosphere Conditions
Food packed in air does not store as well as those in airtight containers. This holds true for dehydrated food as well. The air contains oxygen which leads to compound oxidation in food. Food storage companies have different methods for removing the oxygen while storing dried foods namely:
Displacing oxygen by purging air in the product with inert gases such as nitrogen and dry ice
Absorbing oxygen by using an oxygen absorber to leave gases in partial vacuum such as nitrogen.
How to Store the Dehydrated Food
To get the best storage life of dried products, these must have hermetic or airtight sealing. This includes:
- #10 Cans
- Sealable food storage buckets
- Sealable plastic drums or food quality metal
Oxidation can reduce the flavor and nutritional value of food items. So, vacuum sealing helps to retain the vitamins and nutrients in the food longer.
Some moisture may even get into the packaging so oxygen absorbers are the best choice, Food safe, bags that are semi-permeable, these absorb free oxygen using iron filings and activated charcoal, ensuring food lasts longer. Dehydrating food for long term storage also involves sealing them in glass jars once they are dried. This is because plastic absorbs smell and moisture across time.
Mylar bags and food storage containers with oxygen scavenging facilities built into the packing material also yield good results. Store dehydrated food in cool, dry areas for best outcomes. While herbs can last for years, fruits and veggies generally last for 1 year and meat items dehydrated must be consumed in 2-3 months.
Shelf Life of Dehydrated Food items
If you store dehydrated food in airtight containers at optimum temperature of 60 degree F or lower, the dehydrated foods will last longer. Shelf life of 30 plus years is possible for food items dried and stored properly! High storage temperature lowers shelf life. See the table below to get an idea of how long dehydrated items can last, if the correct procedures are followed:
|Dehydrated Product at 60 Degree F||Years (Long Term Storage)|
|Apples||More than 20|
|Alfalfa Seeds||More than 15|
|Flour from Bakery||15–20|
|Organic Brown Rice||3–5|
|Buckwheat||More than 20|
|Whole Wheat Flour||30|
|Pasta||More than 20|
Once the food has been dehydrated, the problem is the 3 percent moisture in the air regardless of where you reside. The food undergoes reabsorption of the moisture and spoils.
To prevent this, you need to store the dehydrated fruit in a container that is airtight to prevent air from coming into contact with the food. Either you can vacuum seal the container using a home vacuum sealer or use Mylar bags. Another option is to dry can it.
Vacuum sealing works well because it ensures that the fruits and other remains lightweight and you need to store the individual bags carefully to prevent rodents and bugs from getting at them.
The food should also be stored in an area not exposed to light. Use craft paper inside bags to shield dried food from sunlight otherwise it may spoil. Store only one kind of food together to prevent flavor mixing and cross contamination in the event of spoilage.
Do not pack dry food items till they become cool to touch. Air surrounding the dried food should be rich in moisture which is then released when it cools. This is important because otherwise, water droplets can enter the storage container and spoil the shelf life of dehydrated food.
Before they are stored, dehydrated foods must be conditioned or loosely packed in jars for 7-10 days and regularly shaken. If condensation is seen in the jar, the item needs to be dehydrated further.
Store dehydrated foods in small batches to match the freshness and prevent contamination. Store the container in a dark, dry and cool location with a temperature of 60 degree F or less. Store older items on top for easy and quick access.
Why Dehydrate Food for Long Term Storage
Dehydrated food is convenient and easy to store, making it perfect for emergencies. They can be consumed without any extra preparation and make for a healthy snack.
Dehydrated foods that are sufficiently dried do not need refrigeration. You can also eliminate molds, and bacteria through low moisture content of food. Dehydrated food is easy to save and carry. It is nutrient rich and easy to carry out the dehydration process too.
You get great tasting food retaining vitamins and minerals while removing preservatives and additives, resulting in cost savings too. Dehydrated food is light and easy to carry.
It takes less space and can be dehydrated easily. Some goods just don’t work well when canned, fermented or frozen, Most foods can be dehydrated and shelf life, if unopened is 15 plus years, as against conventional canned foods.
Dehydrated foods last 1 and a half years on an average in airtight containers with lids. Milk lasts anywhere from 3-6 months, The food item shrinks 70% due to water loss as a result of dehydration and expands again while rehydrated. Good vitamins remain in the food, as against canned items. Cost is also economical.
All in all, dehydrating foods for long term storage saves money, time and effort. Provided you have an optimal dehydrator to meet your needs, dehydrating foods provides flexibility to the chef or consumer.
The best part about dehydrating foods for long term storage is that you can stock up on season specials. Through the careful process of cleaning, drying and storing food items properly, you can increase their shelf life by years.
They can even last 8-10 years in complete vacuumed chambers at temperatures of 70 degree F, if you follow the right instructions regarding how to prepare the food item for drying. You also need to set the right temperature. If it is too low, water content will remain and the food will spoil.
If it is too high, your food can get burnt outside and remain tender inside. So, choosing the right degree and the perfect appliance can vastly influence the success with which you dehydrate foods for long term storage.
Follow all the steps detailed here and you should be able to make food items such as herbs, spices, fruits, vegetables, meats and cereals last for a long time.
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