You can dry the onions for longer storage via a process known as "drying", or you can dry them for use as a snack or topping using an oven or dehydrator. Regardless of the process you choose, drying onions will be as easy as drinking a glass of water thanks to the following guide.
Steps
Method 1 of 3: Dry Onions Natural to Store Over the Winter
Step 1. Choose the onions with the strongest flavor
Less strong onions cannot be dried as well, so if you want to dry onions for storage over the winter, choose the stronger flavored ones available to you.
- As a general rule, less strong onions are usually larger and have an outer layer the same consistency as paper, they are easy to peel. When you cut them in half, they are juicy and the rings quite thick.
- Strong onions are much smaller and tend to have a stronger outer layer. When you cut them, the rings are significantly less thick and you will start to weep.
- Lighter onions last for a month or two, properly treated. Strong ones, on the other hand, can last all winter, in optimal conditions.
- The same sulfur-rich substance that causes tears when an onion is cut helps slow onion decay, allowing strong onions to keep longer.
- The best known strong onion varieties are Candy, Copra, Red Weathersfield and Ebenezer
Step 2. Remove any leaves with scissors or a knife, and gently remove the soil from the roots
- This step is only necessary if you have just harvested onions from your garden. If you bought them at the store, the leaves and dirt have most likely already been removed.
- Keep in mind that onions should only be harvested after the leaves have begun to weaken and bend downwards, a sign that the plant has stopped growing. You should only use well-ripened onions for this process.
- For best results, you should dry the onions immediately after harvesting them.
Step 3. Transfer the onions to a warm, sheltered area
Place the onions in a shed or pantry with temperatures ranging from 15 to 27 ° C.
- Let them rest like this for a whole week.
- If the weather is still warm and dry outdoors, and you are not afraid that the animals will ruin your harvest, you can also leave the onions on the ground for the first few days. Usually, you'll still want to move them to a garage, shed, or covered porch.
- Be careful when moving the onions. They can get bruised if you bang them together too hard. Ideally, you should avoid touching them during this first phase.
- Do not expose the onions to direct sunlight, doing so would cause uneven drying.
Step 4. Evaluate the possibility of drying them by arranging them in a braid
You can continue drying them by leaving them on a flat surface or by tying the tops to form a braid.
- Braid the onions by cutting all but the three newest leaves. Tie or braid the remaining leaves to the leaves of the other onions to be dried and hang the braid vertically to continue the drying process.
- It is a mere matter of personal preference or space since, according to various studies, keeping them on a plane or intertwining them does not affect the drying process in the least.
- Leave the onions to rest for a total of 4-6 weeks.
Step 5. Shorten the top
As the onions dry out, you should cut the tops two or three times as they shrink. Cut all the rest when the onions are completely dry. The roots also need to be cut off.
- Trim the tops of each onion two or three times throughout the process.
- When the onions are ready, remove the tops completely.
- After the first or second week of treatment, use scissors to shorten the roots up to 6mm.
Step 6. Store the onions in a cool, dry place
During the winter, for example, you can keep them in the cellar.
- Place the onions in a net, wicker basket or perforated cardboard box. Just place two or three onions in a confined space so that each has a sufficient amount of air available.
- At a temperature of 0 ° C, strong onions can keep for 6-9 months, while the less strong ones would only last for 2-4 weeks.
Method 2 of 3: Dry the Onions in the Oven
Step 1. Preheat the oven to 71 ° C
Prepare two or more baking trays by covering them with parchment paper.
- On average, you will need one or two baking trays for each onion you plan to dry with this method. If you are drying a single onion, prepare two trays. If you are using two, prepare three or four trays and so on. It is better to give too much space than too little.
- Make sure the temperature doesn't exceed 71 ° C during the whole process. If that happens, you may end up burning the onions or cooking them instead of drying them.
- The trays should be about 5cm narrower than the inside of the oven to allow for sufficient air circulation.
Step 2. Cut the onions into thin slices
The roots, top and outermost layer must be removed, and the onions must be sliced into 6 or 3mm rings.
The easiest way to slice onions is to use a mandolin. If you don't have this particular kitchen utensil, you can still use the sharpest kitchen knife you have to cut them
Step 3. Spread the onions on the trays
Place the sliced onions on the previously prepared trays to form a single layer.
If you overlap the slices, they would take longer to dry, and you may not get a uniform result. This could create problems for you even later if you find yourself having onions that have not been completely dried which, therefore, would go bad after being mixed with the others
Step 4. Dry the onions in the preheated oven
Place the onions in the oven and let them dry for 6 to 10 hours, turning the trays from time to time.
- If possible, leave the oven door open about ten centimeters to prevent the inside of the oven from becoming too hot. If you can, also put a fan in correspondence of the opening so as to better circulate the air inside the oven.
- Leave about 7 cm of space between each tray and between the upper and lower tray and the oven walls. Air must be able to circulate freely.
- Watch for onions when the end of the process approaches as they could burn if left in the oven for too long. Burning them will ruin their flavor and make them less nutritious.
Step 5. Crumble them when ready
Once ready, the onions will be dry enough to crumble to the touch. You can make onion flakes this way.
- For the onion flakes, crumble the onions with your hands. To make onion powder, put them in a plastic bag and mash them with a rolling pin.
- You can also leave the rings intact, but they will be so fragile and delicate that they will break as soon as you try to handle them.
Step 6. Store them in a cool, dry place
Place the onion flakes in an airtight container and store it in a pantry or similar.
- If vacuum-packed, dried onions can be kept for up to 12 months. Otherwise they last from 3 to 9 months.
- Watch out for any traces of moisture. If you notice any signs of moisture inside the container during the first few days, take the onions out, dry them further and dry the container before putting them back in. Moisture would spoil the onions earlier than expected.
Method 3 of 3: Dry the Onions Using a Dehydrator
Step 1. Prepare the onions
The onions must be deprived of the outermost layer and cut into 3mm thick rings.
- Also cut off the roots and tops of the onions.
- Use a mandolin to slice them, if you have one. Otherwise, use the sharpest kitchen knife at your disposal.
Step 2. Place the onions on the trays of the dehydrator
Arrange them on a single layer, positioning the trays so that air circulation is not impeded.
- The onion slices must not overlap or touch each other. Keep them away from each other to maximize air circulation.
- The trays should be as far apart as possible inside the dehydrator. Leave at least 5-6cm of space between them to maximize air circulation.
Step 3. Leave the dehydrator on for approximately 12 hours
If your dehydrator has a thermostat, set it to 63 ° C and let the dehydrator go until it reaches temperature.
If you have an old or inexpensive dehydrator that doesn't have a thermostat, you will need to check for yourself how the drying is progressing. The time it takes can vary by more or less an hour, and you can check the temperature with an oven thermometer, so you can roughly estimate how much more or less time you might need
Step 4. Place the dried onions in an airtight container
Put the onions in a cool, dry place. Use them in your dishes, or eat them as they are.
- If vacuum-packed, dried onions can be kept for up to 12 months. Otherwise they last from 3 to 9 months.
- Watch out for any traces of moisture. If you notice any signs of moisture inside the container during the first few days, take the onions out, dry them further, and dry the container before putting them back in. Moisture would spoil the onions earlier than expected.
- You can also reduce onions to flakes or powder for culinary purposes.
