Created by: Kathleen Riggs USU Extension Agent, Iron County Home Drying Basics Created by: Kathleen Riggs USU Extension Agent, Iron County

Instructions to modify presentation Copyright: Permission is granted for all use/reuse by U.S.U. Extension. Others may modify the presentation only by placing their logo on the slide master template and adding the presenters name in the footer. The authors name must remain on the presentation. To modify: In PowerPoint choose [View], then [slide master], then select the last slide down. Here you can modify elements common to all slides. You may add a logo USU Extension may replace the upper left logo with the USU Extension logo indicating their county. All may add a logo to the upper right corner. USU Extension may change the bottom left graphic and the footer. To change the footer: Choose [Insert][Header-Footer] and type your footer as a replacement for the existing footer. Extension staff should consider placing their web address and phone number here. When finished editing delete this instructional slide before presenting. Please do not delete any other slides. Please report errors or needed corrections to brian.nummer@usu.edu – Thanks. Foods can be preserved by refrigeration, freezing, dehydrating and canning. Canning can be a safe and economical way to preserve quality food at home. Disregarding the value of your labor, canning homegrown food may save you half the cost of buying commercially canned food. Canning favorite and special products to be enjoyed by family and friends is a fulfilling experience and a source of pride for many people. The advantages of home canning are lost when you start with poor quality fresh foods; when jars fail to seal properly; when food spoils; and when flavors, texture, color, and nutrients deteriorate during prolonged storage.

Drying (Dehydration) One of the oldest methods of preserving food Alternative to canning & freezing Simple, safe and easy to learn Can dry food year round No refrigeration needed Takes little space -Drying is the oldest method of preserving food. Compared with other methods, drying is quite simple and you may have most of the equipment on hand already. -Methods for canning and freezing have been determined by research and experience. Home drying, however, does not have firmly established procedures. Food can be dried several different ways and times set for drying vary depending on the type of dehydrator and how much humidity is in the air.

How Drying Preserves Food Removes moisture stops the growth of bacteria, yeasts & molds that normally spoil food Slows down but doesn’t completely inactivate enzymes Enzymes are what usually causes some foods to brown when exposed to air (apples and bananas). It can change surface color but also off-flavors. These enzymes are usually controlled by pre-treatments to the food which we will talk about later on.

Temperatures for Drying The ideal temperature for drying or dehydrating foods is 140° F If higher temperatures are used, food cooks instead of drys Avoid “case hardening” dried on outside but moisture trapped inside allowing mold growth

Climate Controls Low humidity aids drying Utah average relative humidity in Summer is 20% Illinois average relative humidity in Summer is 50-80% Increasing the air flow with fans speeds up the drying process- removes air pockets around food Consecutive days of sunshine Iron Co., UT has over 255 sunny days per year Washington Co., UT has 300 Dry climates found in much of the Western states with low humidity are ideal for drying foods outside using solar heat. Iron County is ideal with a nearly constant breeze in the air along with sunny skies.

Methods for Drying Food Outdoors (Sun & Solar) Works well in Southern Utah June - September Oven Need temperature of 160° F and frequent rotation Dehydrator Easiest method and most efficient but may have smallest capacity

Drying Foods Outdoors Sun Drying: Fruits safe to dry due to high acid and sugar content Vegetables & meats should not be dried outside They need constant temperature & airflow Temperature of 85° F or higher for several days with humidity below 60% Cover to protect against insects/pests

Drying Outside, continued Solar Drying- Need to construct a dryer with panel(s) Need to stir and turn food several times a day Need several days of sun in a row Vine Drying- Beans & Lentils Dry beans by leaving them on the plant in the pods until the beans inside rattle.

Drying Foods Indoors Methods: Food dehydrator Counter-top Convection Oven Conventional Oven Microwave Oven

Food Dehydrators These are small electrical appliances for drying foods indoors They contain an electric element for heat, fan & vents for air circulation Some have actual temperature controls but usually dry at 140° F Widely available in stores, catalogs and on-line There are a variety of types and styles of food dehydrators on the market. They don’t need to be complicated to accomplish the job.

Common Dehydrator Features Plastic or metal (not wood) Enclosed heating element Counter top design Enclosed thermostat (readings from 85°F- 160°F) Fan or blower 4-10 open mesh trays- made of sturdy, washable plastic UL Seal of Approval 1 year warranty Dial/control for regulating temperature A timer, or auto-shut-off

Types of Air Flow Horizontal Air Flow Vertical Air Flow Heating element and fan are located on the side Major disadvantages: Higher priced Take up a lot of counter space Major advantages: Different foods can be dried at same time without flavors mixing Equal heat distribution No drips on to trays below Heating element and fan on top or bottom of unit Major disadvantages: Dries smaller quantities Trays need to be rotated throughout process for equal drying Major advantages: Smaller units Lower cost Average Price Ranges 6/2008 Small plastic constructed units: $40 Large stainless steel units: $350

Oven Drying If you use your oven: Dial needs to go down to 140°- 160°F Leave oven door open 2-6 inches Best if you place a fan outside oven door to force air movement Oven cycles on and off- make certain thermostat is accurate at 140°F (Hint: Most ovens don’t go this low) Tray size should be 3-4” shorter (front to back); leave 2-3” between racks If you are going to dry foods in an oven, the best ovens to use are convection. They already have a built-in fan.

Oven Drying Slower process than using dehydrators, unless you have a convection range that moves the air Could take twice as long to dry than a dehydrator… oven is not as efficient and uses more energy

Room Temperature Drying Method used mainly for herbs & hot peppers Strung on string or tied in bundles and suspended from overhead racks in air until dry OR Enclosed in paper bags with openings for air circulation Herbs can also be dried in the microwave oven To dry herbs in the microwave oven, place the herbs between paper towels and set them on the rack. Close the door and turn the oven on a medium setting for 2 to 3 minutes. Then check for dryness; the leaves should feel brittle and should crumble easily. If they are not done, turn the oven on for 30 seconds longer. Although this process actually cooks the herbs, the end product is just about the same.

The Process

Drying Fruit Prepare the Fruit- wash, core and peel if desired Fruits can be halved or sliced and some left whole Thin, uniform, peeled slices dry fastest If fruit is whole, “check” or crack the skin to speed drying Apples can be cored and sliced into rings or wedges Bananas can be sliced - Blueberries, cherries, grapes, plums and a few other fruits have tough skins with a waxlike coating. The skin must be “cracked” or “checked” in many places to remove the waxyi coating and to let thie inside moisture come to the surface to evaporate. To crack the skin, put the fruit into boiling water for 30-60 seconds. Then dip in very cold water. Drain thoroughly- Fruits that dry well have “meat” ; citrus peels dry well and some tropical fruits

Drying Fruit, continued Pre-treatment Some fruits need to have enzymes inactivated before drying– especially those that oxidize when exposed to air (e.g. bananas, apples, pears) Ascorbic Acid Fruit juice dip Honey dip Syrup blanching Commercial acids Some of the older food dehydrating books will talk about sulfur treatments for fruit. This uses sodium bisulfite which is difficult to find. If you want information on sulfuring, it can be made available through the Extension Office.

Arranging Fruit for Drying Do not over fill Leave room for air circulation Lay as flat as possible Dry similar fruits together Avoid mixing strong odors

Determining Dryness of Fruit Drying fruit can take anywhere from 6 hours for thin or small pieces or 10-12 hours for larger juicy fruits such as peach or apricot halves. Dried fruit will feel leathery; won’t stick to itself Cut fruit should have no visible moisture inside though it may be soft

After Drying Fruit… Cool fruit 30-60 minutes before packaging… don’t pack too soon or moisture buildup could occur… Don’t wait too long or the fruit could pick up moisture from the air

Conditioning Fruit Conditioning is used to equalize moisture Pack cooled fruit in plastic bag or glass jar Seal and let stand for 7-10 days Shake jars daily to separate pieces and check for moisture (condensation on sides of bag/jar) If there is condensation, return fruit to dehydrator for more drying or place in freezer There is a chance mold will have already started growing in too-moist fruit- Discard if you find mold.

Fruit Leathers Made from pureed fruit Can use fresh/frozen fruit or canned fruit May add sugar, honey, or lemon juice for flavor and color retention May add coconut or nuts Dry on special drying tray that comes with dehydrator Dry until pliable; no wet spots; not crispy Pour 1/8-inch thick puree on drying tray Takes 6-8 hours to dry in dehydrator When warm, peel from plastic tray and roll, cool and rewrap in plastic wrap Keeps at room temperature about 1 month- freeze for longer term storage (1 year)

Drying Vegetables Prepare the vegetables Wash, trim, and peel Cut uniform pieces or leave whole Dry as soon as possible after harvesting

Pre-treating Vegetables Water blanching– Follow recommended times Do not over-fill basket or pan Start timing when water returns to boil after placing vegetables in basket Steam blanching- Place in basket above boiling water (no more than 2 inches higher) Cover pan/pot and begin timing Blanching vegetables is how we inactivate enzymes.

Cooling Vegetables Dip briefly in cold water only long enough to stop cooking Cool until they are only slightly hot to touch– about 120° F Wipe and spread vegetables out on racks for drying

Determining Dryness of Veggies Dry vegetables until brittle or “crisp” Some vegetables shatter if hit hard Low moisture (10%) Cool, place in bags or jars and seal Should store up to 1 year if in a cool dark place in jars with air-tight lids

Jerky Use lean meat (cuts of beef, pork, venison, or smoked turkey breast) If wild game is used, freeze meat for 30 days to kill Trichinella parasite If you are raising your own meat, make certain slaughtered animals do not eat any carcasses of mice, etc. (mostly hogs)

Eliminating Illness Causing Bacteria Dip meat strips in boiling marinade 15 seconds before drying– dry as usual Check temperature of several strips- 160° F is desired temperature Heat dried jerky strips in oven after drying process is completed. Heat 10 minutes in oven pre-heated to 275° F. Thicker strips may take longer. Test internal temp.-- 160° F is target

Determining Dryness of Jerky Jerky should bend and “crack” but not break There should be no surface moisture or visible moisture when cut open Will be somewhat chewy

Storing Jerky Properly dried jerky keeps at room temp for 2 weeks in sealed container. For best results, to increase shelf life and maintain best flavor and quality, refrigerate or freeze jerky and take out as needed

Nutritional Value of Dried Foods Fresh produce provides calories, fiber, minerals and vitamins. Changes that can be expected in home-dried food are: Calories: No change Fiber: No change Minerals: Minimal loss Vitamins: Greater loss during dehydration process (more susceptible to heat, air and light) Calories: The calorie content of the dried food, however, will be higher per unit of weight because nutrients become more concentrated as water is removed. Minerals: No data available. None is lost in the drying process. Vitamins: Those most often found in fruit and vegetables are A,C and the B vitamins. If vegetables are blanched, vitamin A activity is maintained to a high degree. Losses of vitamin C vary widely depending on treatment. Speed in drying and absence of sunlight are advantages in maintaining ascorbic acid. Only moderate losses of B vitamins occur during drying.

Yields Because drying removes moisture, the food shrinks and decreases in size and weight. When water is added to the dried product, it returns to its original size 25 lbs. apples = 4 lbs. dried 25 lbs. onions = 3 lbs. dried =

References “So Easy to Preserve”- University of Georgia Drying Food, University of Illinois Extension Food Preservation: Dehydration- New Mexico State University Home Drying of Food, Utah State University Extension Download: http://extension.usu.edu/files/publications/publication/FN-330.pdf

© Utah State Univ. Extension Utah State University is committed to providing an environment free from harassment and other forms of illegal discrimination based on race, color, religion, sex, national origin, age (40 and older), disability, and veteran’s status. USU’s policy also prohibits discrimination on the basis of sexual orientation in employment and academic related practices and decisions.  Utah State University employees and students cannot, because of race, color, religion, sex, national origin, age, disability, or veteran’s status, refuse to hire; discharge; promote; demote; terminate; discriminate in compensation; or discriminate regarding terms, privileges, or conditions of employment, against any person otherwise qualified. Employees and students also cannot discriminate in the classroom, residence halls, or in on/off campus, USU-sponsored events and activities.  This publication is issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Noelle E. Cockett, Vice President for Extension and Agriculture, Utah State University. Author: Kathleen Riggs USU Cooperative Extension. August 2008.