When using a dehydrator, users may notice the vents on the appliance. This leads to the question, should the vents be left open or closed while the appliance is in use?
There are different answers depending on what type of food is being dehydrated and what the surrounding environment is like.
The vent on the dehydrator should be left open while food is being actively dried out. However, sometimes the vents should be slightly shut when drying out foods without a high moisture content. In rarer cases, the vent should be closed for brief periods. These answers are determined on a case-by-case basis and users should read the manufacturer manual for their dehydrator model.
If you’re uncertain whether the vent should be open or closed, it’s safe to leave the vent open. This is rarely going to ruin the food being dried out and it’s generally how a dehydrator is meant to be used under normal circumstances.
What Happens to Your Dehydrator if You Leave the Vents Closed?
If the vent on a dehydrator were to remain closed during the drying-out process, the food in fact would never become dehydrated. The purpose of the vent is to release the humid air and draw in fresh, dry air. By trapping the moisture inside of the appliance, the food will just continuously reabsorb the water content.
The only time you want to close the vent partway is if you’re struggling to retain heat inside the appliance. This can happen during the winter season when it’s colder than normal and the food isn’t becoming dehydrated due to a lack of heat.
Even then, you’ll want to leave the vent cracked partway to avoid an excessive buildup of moisture. If you’re able to watch the dehydrator, you can close the lid for a short period to allow heat to build up, before cracking it open again.
When using a dehydrator, the vent should stay open. This allows the appliance to function as it was intended and provides an even amount of dry to humid air to be exchanged.
Some people recommend closing the vent when dehydrating items such as jerky, as this speeds up the process. However, this can also cause too much moisture to remain in the meat.
Once food has been fully dehydrated, it can be stored in a sealed environment in a cool, dark place. If there is still too much moisture left over in the food, it can quickly spoil and the process of dehydrating it will be pointless. Nobody wants to open their pantry to find containers of moldy fruit and vegetables.
Dehydrated food is prone to reabsorption, which is why it should be tightly sealed right away. Checking your dried food frequently is recommended, as you should be able to catch any moisture before it’s too late.
Glass containers are a great storage method, as you’ll be able to see if there has been any moisture buildup from a passing glance.
Does Your Dehydrator Need Ventilation?
Dehydrators need ventilation to work properly. When drying out moisture-heavy foods such as fruit — the vent should be all the way open as there is more moisture coming out. If you’re drying out vegetables, such as carrots, then the vent can be slightly less open as there won’t be as much moisture.
Without proper ventilation, moisture is at risk of building up within the dehydrator and this can cause a whole host of other issues. The food being dehydrated may even end up moldy and inedible due to the humidity within the appliance.
Many models of dehydrators come equipped with two vents, an adjustable lid vent, and one at the base of the machine. The adjustable one is the one that users can open or close depending on what they’re trying to achieve. When using a dehydrator, the base lid shouldn’t be blocked as this can prevent adequate airflow.
It’s also recommended to use a dehydrator in a well-ventilated room within the home or even outside. During the process of removing the moisture from the food, the air around the dehydrator can become humid. This is alleviated when the machine is placed next to a cracked window or a kitchen with plenty of circulation.
The last thing you want when using a dehydrator is for the food to reabsorb the moisture that it just lost. This would defeat the entire purpose of the process.
The dehydrator not only pushed out the moist air but also pulls in cool dry air from the surrounding environment. If there is none available, the food won’t ever become fully dehydrated.
Why Would a Dehydrator Blow Cold Air?
A dehydrator that is blowing cold air is often a sign of a mechanic issue within the machine. Cold air means that the food isn’t dehydrating, as warm air is a requirement for removing moisture.
It can be a disheartening experience to come back to your dehydrator after a day at work, only to realize it’s been blowing cold air.
The first thing to check once you notice the cold air is the heating element on the dehydrator. The coil mechanism can burn out and it would need to be replaced before you can get your appliance back up and running.
Attempting to fix the machine by yourself isn’t recommended, as it can be a somewhat dangerous and complicated process.
If your dehydrator is still under warranty, the heating element should be covered and you can get it replaced. If the dehydrator is an older model, it may be worth it to look at a new one.
In other situations, there could be some faulty wiring within the machine. This can cause the heating element to not warm up as it should — thus blowing cold air instead of warm air. You can check the temperature yourself to see if it’s heating up at all or if it’s just simply cold air being circulated inside.
When a dehydrator heats up as normal and works for several hours before inevitably blowing cold air, this could be a sign of overheating.
If the trays have been overloaded with food, the machine is having to work harder to circulate air and get rid of the moisture. This can result in the appliance simply becoming overworked. Next time, try fewer trays with fewer pieces of food on them.
Can Too Much Food Block Air Flow in a Dehydrator?
One of the most important things when it comes to dehydrating food is ensuring proper airflow. Without airflow, food won’t dry out efficiently; overloading your dehydrator with too much can block an even level of airflow.
While it may be tempting to load up every single tray on your dehydrator with delicious banana slices, apple pieces, and even zucchini chips — you should ensure that there is still available room for air to circulate within the machine. Too much food will also increase the drying time.
You’ll want to somewhat space the food pieces apart, allowing small gaps where air can weave around and circulate through the entire inner component. If food is lined up in a way that there are no leftover gaps, this will create issues during the drying-out phase.
For those struggling with a lack of airflow, you can try removing a tray or simply leaving it empty. This allows plenty of extra air to make its way around and evenly dehydrate all of the food on the remaining trays.
It’s important to not overwork the machine, as this can cause overheating which will result in sticky, moist pieces of food left over.
Depending on the type of dehydrator, some have vertical airflow while others have a horizontal flow. Determining which type your dehydrator has can help you in spacing food apart to ensure everything has the chance to circulate and dry out in a reasonable amount of time.