How to Dry Food
There are many ways to store food, but one of the oldest ways known to humankind is by drying it. If you want to know how to dry food, you can learn the steps below. One of the things you have to consider before even starting is that preserving the quality of the food is best done by drying it as near to harvesting as possible.
Two big benefits of drying your own food are that the end results take up less storage space and long term food storage options are greatly improved. If you need an added benefit, consider that food which has been dried has all the richness of flavor packed into a smaller space, so it is tastier.
The three major factors of being able to dry food correctly are:
- Heat without cooking
- Dry air
- Air circulation
When you dry food properly, you end up with a product that has 5% to 25% water content depending upon the type of food you are drying. By removing moisture, you take away the ability for micro-organisms to grow, so the dried food can last longer. It also keeps foods from breaking down so rapidly.
Food Preparation prior to drying fruits or vegetables
Start by washing your hands for 20 seconds under warm water using soap. Then, you can wash your fruits or vegetables under running water before peeling or cutting them. You don't want to scrub any fruits or veggies unless they have thick rinds/skins or you will damage them. You also do not want to soak produce. Just rinse in a colander, if you have one, using a sink sprayer, if at all possible. If you don't have these available, take a strainer and put the fruit or vegetables inside and dip them in a stockpot filled with warm water (no warmer than 10 degrees F warmer than the food being rinsed). If necessary, change the water and dip several times until the water runs clear.
Preparing Vegetables Before Drying
Blanch vegetables in boiling water or a citric acid solution before drying them to stop the foods from breaking down (enzyme activity) and it helps kill harmful microorganisms. This will also improve the quality of the vegetables once they are dried.
To blanch vegetables, fill a large stock pot or kettle with water. If you are adding citric acid, do so as follows: Stir in ¼ teaspoon or 1 gram of citric acid into one quart or 1 liter of water. Make sure the water is always boiling. Never put in more than 1 quart of vegetables at a time. Place vegetables in a square of cheesecloth or a mesh bag and drop them into the boiling mixture leaving them fully covered for at least 4 minutes. The exceptions are Brussels sprouts which need 5-6 minutes and Potatoes which need 7 minutes.
You can check this fact sheet for more details about blanching (and more): Quick Facts about Blanching and Drying Vegetables
Preparing Fruits Before Drying
Fruits need some extra care before drying, too. Any fruit with a pit needs to be pealed and pitted, of course. Cherries, plums, grapes, cranberries, blueberries which are going to be dried whole need to go through a process called "crazing" which cracks the surface. Dip them into a pot of boiling water for 15-30 seconds (or up to 60 seconds depending upon the size of the fruit) and then dip them into cold water immediately afterward.
This process cracks the outer surface of the skin and allows moisture to escape. This speeds the drying time of the fruit. It is not intended to pre-heat the fruit.
One problem that you run into when preparing fruits for drying which we will address here is browning. Some fruits will turn brown quickly due to a process called oxidation. If they aren't treated with an anti-oxidant, they will lose their flavor, color and texture. One way to do this is to dip fruits into fruit juices which contain ascorbic acid. This helps preserve natural coloring and even add some flavor to the fruit. Soak fruit pieces for 3-5 minutes then drain them well before drying using the method of your choice. Any citrus juice is great for this: orange, lime, grapefruit or lemon. It is best to only use the juice twice before replacing it for the next batch of fruit. Your juice is still perfectly drinkable, too.
There are other methods to preserve fruit color, such as using sulfur and sodium bisulfite. As I am not a fan of either of these methods for health reasons, I will let you pursue them in other places if you so choose.
How to Dry Food: Drying Methods
Here is something to think about before actually drying your own food.
Determine if you are going to purchase a dehydrator or if you are going to dry your own food using other methods, such as your oven or the sun. If you are leaning toward making a purchase, here are some options I have researched for you:
- Nesco Snackmaster Express 4-Tray Food Dehydrator is a very quiet machine which does a fantastic job of drying fruits and vegetables. It is not an expensive model, but it works very well and gets great reviews from people who own it. The heat and air come from the top of the unit which makes for better distribution and more even drying.
- Waring Professional Dehydrator costs a little more, but comes with an extra tray. It is easy to clean and you can purchase additional trays.
- Excalibur 9 Tray Deluxe Dehydrator is the model I would buy if I had the money just because of the size. It has enough trays that you could handle your entire grandmother's garden full of tomatoes and still have room left over for your neighbor's zucchini squash.
- Presto Digital Electric Food Dehydrator comes with a variety of trays, so if you want to dry fruit or vegetables, you can do that, or if you want to make fruit leather, you can do that, too. This is one model you can set and forget.
If you would rather learn how to dry food yourself, there are several methods which are presented here:
How to dry food: Oven Method
Pre-heat your oven to 145 degrees Fahrenheit. If your oven will not go this low, set it as low as it will go and keep the oven door open slightly with a fan blowing on low toward the opening to improve circulation and to allow moisture to escape. This will keep the food from getting too hot, too quickly. Newer model ovens can be set to the appropriate temperature and have a moisture release vent near the back of the top of the stove, so this is not a problem.
Watch your food to ensure it does not overcook or cook unevenly. Stacking trays on racks in the oven is fine, but you will want to rotate to different racks – and even turn the food on the trays – to ensure food is cooked evenly throughout. This is especially true if you have thick layers of food on each tray.
How to dry food: Sun Method
Only fruits high in sugar and acid should be dried in the sun as other foods will spoil. Humidity needs to be below 60% in order for the sun drying method to work. Hot, dry days with a temperature of at least 85 degrees F and a light breeze are ideal.
Fruit should be placed on a lined cake rack or a screen so that air is able to circulate around the food. Having the trays or screens raised above the ground, such as on sawhorses or blocks is important. Screens made from metal will maintain a higher temperature than something made from wood, so the drying time will be faster. Also, placing the cake racks or screens over concrete will speed up the drying time due to increased reflective heat.
Protecting fruits as they are drying is important as birds and bugs will want to sample your delicacies. Another screen or cheesecloth covering the food should do the trick.
Do not use solid metal trays or cookie sheets when drying fruits as the air can't circulate around the fruit and it will spoil before it can ever dry. Galvanized metals are also a bad choice as the metals are harmful when combined with the acid in fruit.
After you have dried your fruits and vegetables
There is a process that can make your home dried fruits and vegetables even better. This process is called conditioning. It takes a little time, but it will allow your end product to taste better, be more uniform and last longer.
Since drying food isn't as precise a process as anyone would really like, some pieces of fruit, for example, will contain more moisture than others. For this reason, you can take a quart size canning jar and fill it two-thirds of the way full with your dried fruit (or vegetables) and leave them on your kitchen counter for 2-3 days. Once or twice each day, give the jar a shake to re-distribute the fruit and allow the air to move around a little. The moisture in each of the fruit (or vegetable) pieces will distribute more evenly among all of the pieces that way.
Now that you know how to dry food you will be on your way to making and putting away a lot of food each summer for your family. This is an awesome way to prepare for a variety of situations, including disaster scenarios.
I will cover home food storage of dried fruits and vegetables in depth in another article.