The more you know about food dehydrators in general, the more informed you will be when you buy one. Food dehydrators are basically simple machines: They create an environment in which water is removed from food. The machines vary in design, size, price, and effectiveness and, as a consequence of any or all of these factors, they can turn out very different qualities of dried-food products.
Over the years, home food dehydrators have become more sophisticated and the quality of the foods dried in them has improved. Updated features on the machines encourage the food-drying enthusiast to experiment with different varieties of foods because the results can be so gratifying. For example, years ago I experimented with drying carrots and orange juice together in an attempt to make a special breakfast leather to take on a camping trip. Unbeknownst to me, I had added too much sugar, I had not oiled the solid leather sheets, the dehydrator I was using had neither temperature control nor adequate air flow, and what I ended up with was dark-colored, sticky, sticky goo! Recently, I tried again, using a different dehydrator: I combined homemade fresh carrot juice with thawed orange juice concentrate, poured the mixture on lightly oiled solid leather sheets, and dried the puree at 135°F. Some hours later I had just the product I wanted. The leather was a little sticky, but it tasted great and had a good color; it peeled right off the drying surface, made a great snack, and when I rehydrated it into a breakfast drink, it put some commercially dried orange juice products to shame. Because the dehydrator I use works well, my ongoing experiments at food drying are very rewarding.
In selling dehydrators at home shows and state and county fairs, I have discovered that when people buy their first machine, a lot of the time what they are really buying is the concept. They like the idea of home food drying, they want a dehydrator, and their only question is “How much does it cost?” I can understand that cost is an important consideration—people can only afford to spend so much—but it is not necessarily the best place to start. Interestingly, I now sell more dehydrators to people who are buying their second or third one because they bought their first machine thinking of price alone.
Dehydrators can be purchased for as little as $30 to $40, with more sophisticated ones costing from $100 to $300. Instead of concentrating on the price, I encourage prospective buyers to ask, “How does it work?” When you understand how something works, you are more apt to use it, making however much money you spent on it well worth it.
With a food dehydrator, you need adequate heat and air flow, so it is very important that you find out before buying the unit how the air is heated and how the dry air is circulated (if it is), and whether or not you have any control over these facets of the machine. There are a lot of inexpensive food dehydrators on the market. Some of them do not have a fan, and because of their vertical air flow pattern, it is difficult to dry fruit purees into leathers. Other machines do not have a temperature control. Of course, you can manually rotate the trays, thus moving the food on the bottom to the top of the machine, making the food-drying process more even throughout and producing a product that dries faster and has a better color. Assuming that you are going to like dehydrated foods, one of those rudimentary models may not be up to the tasks you have in mind for it. (And you may become weary of having to move trays about all the time.) Also, as with many lower-end models of small electrical appliances, there is a certain built-in obsolescence. My experience, and it is over a twenty-year period now, says buy better for more satisfying and versatile results.
ELECTRIC FOOD DEHYDRATORS
Electric food dehydrators eliminate much of the guesswork in food drying and provide you with options of being able to dry food anytime, day or night, whatever the weather. As mentioned above, if the food dehydrator you have does not have a fan, you may not be able to dry foods overnight or while you are out of the house, due to the need to rotate the trays.
The major components of an electric food dehydrator include:
• a source of heat
• air flow to circulate the dry air
• trays to hold the food during the drying process
• accessory mesh and solid leather sheets to ensure the successful drying of certain types of foods
A Source of Heat
A food dehydrator heats air and it is the hot, dry air that absorbs the water from the food placed in the dehydrator. Over the years, various devices have been used to heat the air: electric light bulbs, coils, nycromium wire, as examples. In the most rudimentary form, a food dehydrator that does not have either a fan or any means of controlling temperature relies on the age-old principle of hot air rising, thereby drying the food contained in the drying chamber.
As the design of electric food dehydrators has become more sophisticated, control features for both temperature and air circulation have been introduced. One type of temperature control has a thermostat with mechanical contact points, which shuts off the electricity (and the heat) when they expand. When the machine cools down and the contact points “contact” again, the heating unit automatically switches back on. This on-and-off-again feature attempts to maintain a consistent temperature in the machine. The problem is that the contact points can wear down over time. As to the accuracy of the temperature with this type of thermostat, there is roughly a ten-degree variance, which means if you set your dial at 135°F, the temperature in the unit may vary from 130°F to 140°F.
An even more sophisticated design of food dehydrator includes solid-state circuitry, which means more reliable temperature control and no moving parts to break. With solid-state circuitry, you can expect the temperatures to be accurate within two or three degrees of the desired setting.
Some new models feature digital thermostats along with electric timers. Lastly, some food dehydrators on the market today have temperatures, preset at the factory, between 130°F and 140°F. Even though these temperatures are preset, actual temperature in the unit can vary as much as ten degrees, meaning that if it is preset to 135°, it can range between 130°F and 140°F.
As to the wattage of electrical food dehydrators, and this again depends upon the brand and type of unit, it can range from 115 to 1,000 watts. Of course, the higher the wattage, the faster the potential for drying food, which, naturally, impacts on the drying time.
A Source of Air Flow
In design, electric food dehydrators can be round, square, or rectangular in shape. Two styles predominate—the cabinet and the stackable unit.
The cabinet-style unit resembles a microwave oven, with a door and sliding, removable drying trays. The heating element is in the back or on the side, and a fan blows the heated, dry air through the drying chamber. In this type of unit, the number of drying trays can range from four to twelve. However, you can dry food on only one tray, if desired.
The stackable style of dehydrator, most of them round in shape, have a heat source at the base of the unit. Many, but not all, stackable units have fans at the base of the unit. With many of these units the number of trays that can be stacked on top can be increased or decreased depending upon the amount of food to be dried. Some dehydrators can utilize as many as thirty-five drying trays. Some stackable designs also have a cover or a lid.
Food dehydrators without fans are known as “passive” units and work on the principle of hot air rising. Air is heated at the base of the unit, then rises, absorbing the moisture in the food on the drying trays it passes through. However, by the time it reaches the top drying tray, the air may already be heavy with moisture and unable to absorb as much water from the top tray of food as it did from the bottom one. As noted earlier, for best results, you will most likely want to rotate the drying trays in a passive unit to compensate for a lack of control over air flow. Given that the best time to dry food is at night (or while you are out at work), this means you then have to set your alarm clock, get out of bed, make your way down the stairs in the middle of the night, turn on the kitchen light, rotate the trays, and then make your way back to bed and to the dream you were having before the alarm jarred you from your slumber! To my mind, this is baby-sitting a food dehydrator, and for obvious reasons most people do not want to use a machine that requires that amount of attention. And they don’t.
A food dehydrator with a fan is called a “nonpassive” unit. Some dehydrators give you control of the fan and therefore of the amount of air flowing through the drying chamber. The more dry air that is created, the faster the drying process. And the higher the wattage of your machine, the faster the drying process. Many food-drying enthusiasts have told me that they value a fan-control feature enormously because they are not enslaved to their machines. In fact, a man in Fresno, California (the raisin capital of the world), told me that he likes to dry his grapes at 130°F, with minimal air circulation. In this way, he says, he is replicating the slow process of sun-drying, which, he also noted, increases the sugar content of the raisins by 30 percent.
Air flow patterns vary with different dehydrators. The pattern of how the air is distributed in the unit is very important. The more sophisticated electric food dehydrators give you control over the temperature and the speed of the fan. Needless to say, with that amount of control over the food you are drying, the results can be excellent. Units with both of these features are among the more expensive you can buy.
One final point about fans and air flow in some electric food dehydrators is that a fan can make a pulsating sound: This is normal.
Drying Trays
As already mentioned, the sizes of food dehydrators vary, as do the designs. As a consequence, the drying trays that fit in them vary in size and shape and number as well. All drying trays—no matter the shape or size—have holes in them to allow the air to pass through. Some dehydrators allow you to add on trays to adjust for the amount of food you have to dry. This can be a real advantage when you find yourself with a lot of extra food to dry in a short period of time.
Two important facts you will want to know about drying trays in general is how to clean them: One, do they fit in the dishwasher (some do not); and two, if they do fit in the dishwasher, are they dishwasher safe? This may sound insignificant now, but when you are staring at a stack of thirty-five used drying trays, you will want to know how best to wash them! After they are washed, I simply put them back in the food dehydrator and turn on the unit. The trays, as might be expected, dry beautifully and you have the added benefit of having already stored them.
Accessory Sheets
Two types of sheets—mesh and solid leather—will enable you to dry many food items that simply cannot be dried directly on the drying trays.
Mesh sheets are plastic sheets with small holes in them that are placed directly on top of the drying trays. The purpose of a mesh sheet is (1) to keep food that contains considerable sugar—bananas, tomatoes, and watermelon—from sticking to the drying trays; (2) to prevent small pieces of food—celery, corn, and herbs—from falling through the drying trays; (3) to hold the juice from a food, through a type of capillary action, next to the food that is being dried; (4) to help prevent moisture from the food on one drying tray from dripping onto lower trays in the drying chamber.
Solid leather sheets actually are liners placed in the drying trays and are used for foods—fruit and vegetable purees, spaghetti sauce, yogurt, and other items that are very high in liquid content—which cannot be dehydrated directly on the drying trays or mesh sheets because they would drip through. Solid leather sheets go by different names and, depending upon the make of dehydrator, may be made of different materials. If your unit does not come with solid leather sheets, check with other dehydrator manufacturers to see if you can adapt their sheets to your machine. An alternative is to stretch plastic wrap over the drying trays and up over the edges to act as a liner. It is helpful to remember that when using solid leather sheets, and mesh sheets as well, that by lightly oiling them you can prevent foods from sticking to them.
Mesh and solid leather sheets are often used together to dry foods that contain a great deal of fat—ground beef, bacon, salmon, commercially prepared luncheon meats, to name a few. In certain instances, you may have to use both types of sheets and also remove the food to blot up any fat that comes to the surface as the food dries. You may also insert both types of sheets (leather on the bottom and mesh on top) when drying foods that shrink to very small pieces, such as rice or dried garlic.
To clean mesh or solid leather sheets, rub them with warm, soapy water, let sit for a few minutes, and rinse them well. Rub really sticky places gently with a scrub brush. Solid leather sheets can become stained—from food coloring—and in those instances, I keep those sheets aside and use them exclusively for the food that has originally stained them, such as certain brands of commercial spaghetti sauce or tomato paste.
Now that you have a basic understanding of what a food dehydrator looks like and how it works, here is a list of questions you should be able to answer before you purchase a unit. Over the years I have repeatedly been asked these by prospective customers, and it is fascinating to observe the freedom that comes from knowing the answers. Find out:
How does the machine work? What is the heat source? Does the unit have a fan? Are there controls and are they easy to use? Does the unit have solid-state circuitry or a mechanical thermostat? Has the make been tested and approved by the Underwriters Laboratories?
What is the square footage of the drying trays? How much food can be dried at one time? Can more trays be added? How are additional trays and accessory items purchased after the initial sale?
Is the machine easy to load and unload? How much does it weigh?
What is the wattage of the unit? The range for electric food dehydrators is from 115 to 1,000. What is the cost to use?
What are the terms of the warranty? Is the machine repairable, or can you fix it yourself? Is it designed for continuous, long-lasting use? If you have to send it to a service center, what will it cost to repair? And how long will you be without your dehydrator? (These questions may seem a little alarmist in nature, but I assure you that the answers, even if you never need them, are important.)
Can food purees be dried in the dehydrator you are considering? Does it come with mesh sheets? Solid leather sheets? How many of each? How and where can you buy more?
Do you have to rotate the drying trays to get air to circulate evenly over all the surfaces of the food for a good-quality product?
What kind of sound, and how much of it, does the unit make?
Is the machine easy to clean? Is there any special treatment for cleaning that you need to know about? Are drying trays dishwasher safe? Are they durable? How often will you need to replace them, and where do you obtain them?
Does the machine you are considering have a built-in timer and automatic shutoff? These two features may prove to be very helpful. Realize, however, that when you start using this type of machine, you’ll need to refer to the instruction manual for directions on what size piece the food you are intending to dry should be cut and how long it should be dried. Food can spoil if the dryer shuts off automatically and you do not remove the food before it reabsorbs moisture from the air.
If the model is a cabinet type, is the door removable for cleaning purposes and accessibility? Does it open, close, and seal easily? Can you see into the drying chamber? How do the trays in this design slide in and out?
Congratulations! With satisfactory answers to the above questions, you are now the owner of a brand-new food dehydrator. I know that what I am about to say may sound simpleminded, but I want you to be sure to take your new purchase out of the box when you get home! I cannot tell you the number of times I have heard people tell me that they never even took their dehydrator out of its original carton.
Yes, take it out of the box, put it on the kitchen counter, plug it in. Now, check out how it works. Using the directions, turn it on; put your hand over (but not on) the heat source; check out the air flow. Examine the drying trays and accessory sheets. Wash them.
Be sure that you have put your dehydrator in a convenient place in the kitchen, one that encourages use. You need easy access to it. Dehydrators that do not make it into the kitchen and end up stored in the garage or basement are dehydrators that are infrequently (if ever) used. If the unit sits in front of you on the kitchen counter, you are more likely to think of slicing and drying the bananas that are overripening in the fruit bowl instead of throwing them out. With your dehydrator handy and your using it an ongoing pleasure, see if you don’t have energy-producing, nutritious, fat-free foods more and more often.
A final tip before we get down to how to use your food dehydrator now that you have it: Remember that after buying any small or large appliance, it is a good idea to keep the warranty, sales slip, and any other pertinent information regarding the purchase. Your receipt should also include an address for repairs. Should your machine at some later date stop working—the two most common problems are that it no longer heats or there is no air circulation—be sure to tell the repair service what appears to be the malfunction. If you do not identify the problem, you will be surprised at how long it can take to get service on it.