by Karen Ward
An electric dehydrator dries your food by heating the air inside the chamber to a low temperature and circulating the warm air through the chamber with a fan, passing the heat evenly over your food for the entire drying process. After you place your food in your dehydrator, it needs little or no attention.
To use an electric dehydrator, follow these steps:
1. Prepare your food according to the recipe and arrange it carefully on the drying trays.
2. Following the instructions for using your dehydrator, allow the food to dry for the specified period of time.
Turn the pieces of food and rotate the trays from bottom to top to ensure even drying of all the food in the dehydrator.
3. Test your food for doneness and then label and store it in an airtight container.
Each time you use your dehydrator, review the operating instructions including preheating the unit, filling the trays, setting the temperature, and the time recommended for drying your food. If you have any questions regarding the use or operation of your unit, contact the manufacturer. You can find this information in your owner's manual or check with the store you purchased it from.
Figure 16-1: Two examples of electric dehydrators.
If you're purchasing a dehydrator, carefully assess your needs. Then consider the following factors when making your final decision:
Overall construction: Purchase a unit that's approved for safe home use by the Underwriters Laboratory (UL). If the unit isn't UL approved, don't buy it — it may not be safe for use in your home. Choose one with insulated walls that's easy to clean and drying trays that you can move easily in and out of the dehydrator without disturbing the food.
Capacity: Purchase a dehydrator big enough to hold the amount of food you'll dry at one time. Typically, the most common-sized food dehydrator has four trays. Each tray holds about 3/4 to 1 square foot of food. Some dehydrators expand to utilize 30 trays at one time. Snack-size dehydrators with two trays are also available.
Heat source: Select one with an enclosed heating element. Wattage needs to accommodate about 70 watts for each tray the unit holds.
Fan: The fan circulates the heated air around your food. Purchase a dehydrator with a quiet fan, because it runs for long periods of time. If your unit isn't equipped with a fan, you need to rearrange the trays more often during the drying period for an even drying.
When buying a dehydrator secondhand, always plug it in to hear how it sounds when running. The level of noise is not an indicator of quality, but a loud dehydrator needs an out-of-the-way place to run, or it'll be too inconvenient to use.
Thermostat: Purchase a dehydrator with an adjustable thermostat. Your temperature options need to range from 85 to 160 degrees.
Drying trays: Check for trays that are sturdy and lightweight; made from a food-safe product like stainless steel, nylon, or plastic; and easy to clean. Some manufacturers offer dehydrator accessories like extra drying trays and trays for drying fruit leather and herbs.
Cost: Dehydrator prices may start as low as $65 and go up to $200 or more.
Warranty: Check out the warranty term (one year is a good average) and any restrictions the manufacturer has for your dehydrator.
A conventional oven
If you have an oven — gas or electric — that maintains a temperature between 130 and 150 degrees with the door propped open, you can use your oven to dry food.
Your oven must maintain a temperature of 130 to 150 degrees for 1 hour to safely dry food; maintaining these acceptable temperatures is difficult unless your oven can be set at less than the standard 200 degrees as the lowest temp. The problem with higher temperatures is that they cook — they don't dry — the food. To test your oven's temperature, put an oven thermometer in the center of your oven with the door propped open.
Oven-drying takes longer than using a dehydrator and costs more because the oven uses a greater amount of electricity than an electric dehydrator does. In addition, if you use your oven for drying, it isn't available for any other use during that time.
To dry food in a conventional oven, follow these steps:
1. Preheat your oven to the temperature setting in your recipe.
Use a separate oven thermometer to check for accuracy. Check the oven frequently to be sure food isn't over- or underdried.
2. Wash and prepare your food as directed in your recipe.
3. Place your filled trays in the oven and leave the door propped open to allow moisture to escape during the specified drying time.
If you use baking sheets or other trays without holes or openings in the bottom, you must turn your fruit to achieve an evenly dried product. After the first side of the fruit has absorbed all the liquid on the top of the food, turn it over and repeat this for the other side. After this has been done on both sides, turn the food occasionally until it's done.
4. Test your food for doneness and then label and store it in an airtight container.
The sun
Sun-drying is the oldest and least expensive of the three methods and it lets you dry large quantities of food at one time. But — and these are big buts — it's dependent on perfect weather conditions to produce a safely dried product and it can take days compared to hours in a dehydrator or a conventional oven.
Weather conditions must be perfect for sun-drying, making only a few climates suitable for this method. The ideal temperature for sun-drying fruit is 85 degrees or hotter for many consecutive days, with the humidity level low to moderate. If your temperature drops more than 20 degrees below your highest temperature during the drying period, your conditions are not suitable for this method. You also need good air circulation, a minimum of air pollution, and insect control around the food. Sun drying is even less attractive for drying vegetables because the temperature needs to be at 100 degrees or above for a number of days with the lowest evening temperature never dropping below 80 degrees (even at night) and the humidity level needs to be low.
Sun-drying isn't safe for meats and fish because the low-acidity level of the food, the low drying temperature, and the long drying period (taking many days) don't destroy the bacteria that cause your food to spoil.
If you're willing to deal with the variances in weather conditions and the lengthy drying time, follow these step-by-step instructions:
1. Wash and prepare your food as specified in your recipe.
2. Line your drying trays or racks with a double layer of cheesecloth or nylon netting.
3. Place your food on the tray and cover your trays with a single layer of cheesecloth or nylon netting to protect your food from insects and dust.
Stretch the cover tightly over the trays, but don't let it touch the food.
4. Place your filled trays on benches or tables in full sunlight and check regularly.
Check your trays at different times of the day, keeping them in full sun at all times. If your nighttime temperature varies more than 20 degrees from the temperature at the hottest part of the day, move your trays to a warmer area (indoors or an enclosed patio area) for the evening, returning them outside when they can be in full sunlight. Relocate the trays if it rains, regardless of the temperature.
If you use baking sheets or other trays without holes or openings in the bottom, you must turn your fruit to achieve an evenly dried product. After the first side of the fruit has absorbed all the liquid on the top of the food, turn it over and repeat this for the other side. After this has been done on both sides, turn the food daily until it's done.
5. Check your fruit daily for evidence of mold (refer to "Other tips for successful drying" earlier in this chapter).
6. Test your food for doneness and then label and store it in an airtight container.
If one day is hot and sunny, yet the next is cloudy, you have a problem because mold can develop on partially dried foods before the weather turns back to hot and sunny again. In this situation, you need to use an alternative to sun-drying to finish the foods.
Protecting the Life of
Your Dried Food
You'll receive many months of rewarding flavor from your dried foods when they're protected from air, moisture, light, and insects. Generally speaking, food dried and stored properly can be kept from six months to one year.
Cooler air provides a longer shelf life for your food. The best storage temperature is 60 degrees or colder. This will hold your food for at least one year. Temperatures between 80 and 90 degrees preserve the quality of your dried food for only about three to four months.
Check your unused dried food from time to time for any visible moisture or spoilage. If the food has signs of moisture, such as droplets of liquid in the containers, your food isn't completely dried. Use it immediately or repeat the dehydrating process and repackage it.
Suitable storage containers include the following:
Glass: Home-canning jars with two-piece caps (see Chapter 2) are a perfect choice for storing dried food. Wash them with hot soapy water and rinse them well or wash them in a dishwasher. Dry and cool your jars completely before filling them and adding the two-piece caps. Reusing glass jars with lids also works well. Remove the cardboard liner that sometimes lines the underside of the plastic lid before washing and filling with herbs.
Plastic: Heavy-duty (freezer) plastic bags with locking zipper-style seals work well. After placing your dried food in the bag, roll the bag to remove any extra air and press the seal together, making the bag airtight.
Metal: If you buy coffee in cans, line the inside of a clean can with heavy plastic wrap, place your food inside, and add the tight-fitting lid.
Vacuum sealers: If you own one of these units, now's the time to use it. Check your owner's manual for operating instructions and start packaging your dried food.
Always label your container with the type of food it contains, the date of processing, and, if you measure your food before placing it into the storage container or bag, list the amount.
Because some pieces of fruit contain more moisture than others, be sure all your fruit is dried the same for storage. Try this tip from the Oregon State Extension Office: Fill a plastic or glass container with cooled, dried fruit about 2/3 full. Cover or seal tightly. Shake the container daily for two to four days. The excess moisture in some of the fruit will be absorbed by the drier pieces. Vegetables dry almost completely, so you don't have to do this with them.
Chapter 17: Snacking on the Run: Drying Fruit
In This Chapter
Preventing your fruit from changing color
Managing the level of moisture in your dried fruit
Returning life to your dried fruit
Recipes in This Chapter
Dried Apples
Dried Apricots
Dried Bananas
Dried Blueberries
Dried Cherries
Dried Citrus Peel
Dried Grapes
Dried Peaches
Dried Pears
Dried Pineapple
Dried Plums
Dried Strawberries
Dried Fruit Medley
Fruit and Bran Muffins
Fruit Leather
This chapter discusses the rewarding process of drying fruit. Dried fruit has many uses — from snacks to sauces, dessert toppings to baked-good fillings. Many of the best fruits for this method oxidize and brown easily when their flesh is exposed to air. This chapter introduces you to the options available to you to prevent any color change in your fruit.
The times required for drying fruit may take anywhere from a few hours to many days. An electric dehydrator provides you with the shortest drying time and produces the best dried fruit of the three methods discussed in Chapter 16. Sun-drying is the lengthiest process and requires a lot of your attention as well as perfect weather conditions.
Putting Your Fruit in Order
Using the best, perfectly ripe fruit for drying is important for a dried fruit that's worthy of high marks and rave reviews. Most fruit is suited for this process with a few exceptions. Fruits not recommended for drying include avocados, citrus fruits (except for the peel), crab apples, guavas, melons, olives, pomegranates, and quinces.
Sizing up your preparation options
Drying time is determined by the moisture in your fruit, the size of your fruit pieces, the moisture in the air (even if you're using a dehydrator or an oven), and the pretreating method you choose. Larger pieces of fruit take longer to dry than smaller pieces of the same fruit. So the smaller you cut your peaches or the thinner you slice your bananas, the less time you need to produce a safely preserved dried product.
Pretreating your fruit
Pretreating makes your fruit look good by preventing oxidation and discoloration, the darkening of the fruit flesh after it's exposed to air. This process retards the enzyme activity in the fruit that causes it to ripen.
Pretreating only slows down the ripening process in fruit; it doesn't stop it.
Using a pretreating method before drying your fruit isn't as important as when you're canning fresh fruit. In fact, it's not necessary at all, but it does assist you with the drying process by shortening the drying time.
The following section explains your pretreating choices.
At one time, sulfuring fruit was popular for preserving fruit color and vitamins in dried fruit. Sulfur is unsafe for any drying method other than sun-drying because the sulfur produces dangerous fumes of sulfur dioxide when it's heated, which occurs when you dry fruit in an oven or a dehydrator. People with asthma or other allergies should avoid this product.
Water blanching
Water blanching is the best for maintaining the bright fruit color. Immerse the fruit in boiling water for a short period of time and then immediately plunge it into ice water to stop the cooking process started from the boiling water. Drain the fruit well.
Steam blanching
Steam blanching is the most common method used for fruit. The steam quickly heats the fruit, shortens the drying and rehydrating times, sets the color and flavor, and slows down the enzyme activity, in some cases killing microorganisms (refer to Chapter 3). In fact, fruit retains more of its water-soluble vitamins and minerals from steam blanching than water blanching.
To steam blanch, hang a colander on the inside edge of a pot of boiling water, making sure the colander doesn't touch the water. Place your fruit in the colander and heat it as directed in your recipe. Cool your fruit quickly in a bowl of ice water. Drain the fruit well.
Dipping in a solution
With this method, you immerse your fruit into a liquid or a solution to control darkening. Dipping the fruit helps it retain vitamins A and C that are lost during the oxidation process. You can use any of the following liquids:
Lemon or lime juice: Fresh citrus juice is the most natural of the dipping solutions. Mix 1 cup of juice with 1 quart of water. Soak the fruit no longer than 10 minutes; drain thoroughly before drying.
Ascorbic acid: This white, powdery substance is available in drugstores. Its common name is vitamin C. Dissolve 1 tablespoon of powder in 1 quart of water. Don't soak your fruit longer than 1 hour; drain it well before drying.
Commercial antioxidants: These products are found in supermarkets or where canning supplies are sold. Some common brand names are Fruit-Fresh and Ever-Fresh. Follow the directions on the product package for making your solution and determining the soaking time.
Detailing Your Fruit-Drying Expertise
Properly dried fruit produces a superior product for use at a later time. After your fruit is dried, labeled, and stored (check out Chapter 16), you'll have delicious and healthful fruits at your fingertips all year round.
Fruit contains a lot of water, and you may be surprised at just how much volume you lose when you dry it. So don't be put off by the amount of fruit you start with, wondering where you're going to store it all. Four pounds of fresh blueberries, for example, makes 1 1/4 cup dried blueberries. And the best news? All the taste and nutrition is still there. The only thing missing is the water.
Knowing when your fruit is properly dried is important. Normally, touching and tasting a cooled piece of fruit gives you the answer, but when you're in doubt and you positively, absolutely need to know the moisture in your fruit has reduced enough, follow these basic steps:
1. Prepare your fruit and weigh the portion you'll be drying.
2. Look up the amount of moisture (water content) in your fruit.
You can find this information in the recipes list in this chapter.
3. Determine the total water weight of your fruit.
Multiply the weight of your prepared fruit before drying by the water content percentage. For example, you have 20 pounds of prepared peaches with a water content of 89 percent:
20 pounds of peaches × 0.89 water content = 17.8 pounds of water
4. Calculate the amount of water (by weight) that needs to be removed from the fruit during the drying process.
Multiply your total water weight (your answer from Step 3) by 0.8 (the minimum amount of water you want to remove from your fruit during the drying process). Using the peaches example
A total water weight of 17.8 × 0.8 = 14.24 pounds of water to remove
5. Determine how much the fruit should way after drying.
Subtract the amount of the water you want removed (your answer from Step 4) from the total weight of the fruit you prepared for drying (your answer from Step 1). Example
Twenty pounds of prepared fruit - 14.24 pounds of water to remove = 5.76 pounds of dried fruit as your goal
6. Weigh your fruit when you think it's done.
If your fruit weighs the amount you calculated in Step 5 or less, your processing is successful. If your fruit weighs more than this amount, return it for more drying.