Drying Foods

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Drying Foods

• Jananne Finck, MS, RD.
• Nutrition Wellness Educator
• Springfield Center

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Drying is New Again

• One of the oldest methods of preserving food
• Alternative to canning freezing
• Simple, safe and easy to learn
• Can dry year round
• No refrigeration needed
• Takes little space

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How Drying Preserves

• Removes moisture from food so bacteria, yeasts
  molds cant grow and spoil food
• Slows down action of enzymes but doesnt
  inactivate them

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Temperatures for Drying

• Optimum temperature for drying food is 140F
• If higher temps are used, food cooks instead of
  drying
• Avoid case hardening dried outside and
  moisture is trapped inside mold results

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Helps Drying

• Low humidity aids drying
• Increasing air current speeds up drying, removes
  air around food

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Ways To Dry Food

• Foods can be dried in the sun, but often doesnt
  work well in Illinoisneed several days of high
  temp and low humidity
• Dry in an oven
• Dry in food dehydrator

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Drying Out-Of-Doors

• Sun Drying
• Dry fruits, high sugar acid make them safe
• Dont dry vegetables or jerky/meat outdoors
• Need hot, dry, breezy days
• Temp of 85ºF. or higher, for several days with
  humidity below 60
• Need to cover, watch materials used and control
  for insects and pests

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Out-Of-Doors

• Solar Drying
• Need to make a dryer
• Need to stir and turn food several times a day
• Need several days
• Vine Drying
• Dry beans, lentils and soybeans
• Leave bean pods on vine until beans inside rattle
• If not dried can dry further in oven or
  dehydrator

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Pasteurization

• Freezer Method seal food in freezer plastic
  bags. Freeze at 0ºF for at least 48 hours

• Oven Method Place food in single layer on fray
  or in shallow pan. Place in oven preheated to
  160ºF for 30 minutes

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Drying Foods Indoors

• Food dehydrators
• Counter-top
• Convection ovens
• Conventional ovens

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Food Dehydrators

• Small electrical appliance for drying foods
  indoors
• Electric element for heat fat and vents for air
  circulation
• Dry foods fast at 140ºF
• Buy at department stores, mail-order, garden
  supply, internet

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Costs?

• Costs vary depending on features. Some are
  expandable extra trays can be purchased. Twelve
  square feet of drying space dries about a
  half-bushel of produce.
• Major disadvantage of dehydrator is limited
  capacity.

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Dehydrator Features

• Double wall construction of metal or high grade
  plastic, not wood
• Enclosed heating element
• Counter top design
• Enclosed thermostat from 85ºF-160ºF

• Fan or blower
• 4-10 open mesh trays, plastic, sturdy, washable
• UL seal
• 1 year guarantee
• Convenient service
• Dial for regulating temp
• A timer, auto- shut off

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Types of Dehydrators

• Horizontal Air Flow
• Heating element and fan are located on side
• Major advantages reduces flavor mixing so
  different foods can be dried at once, all trays
  get equal heat, juices dont drip into heating
  element

• Vertical Air Flow
• Heating element and fan located at base
• Major disadvantage
• if different foods dried, flavors can mix and
  liquids can drip into heating element

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Oven Drying

• Slower than dehydrators, unless you have a
  convection oven, which has a fan
• Take 2 times longer to dry in oven than
  dehydratoroven not as efficient and uses more
  energy

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Using Your Oven

• Dial needs to go down to 140ºF
• Leave oven door propped oven 2-6 inches
• Best if you place a fan outside oven door
• Oven temp variesso need accurate oven
  thermometer to be sure 140 is achieved
• Trays should clear sides of oven 3-4 shorter
  front to back of oven, 2-3 between racks in oven

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Room Drying

• Herbs, hot peppers, nuts in shell are most
  common air dried foods
• Herbs peppers strung on string or tied in
  bundles and suspended from overhead racks in air
  until dry.
• Can enclose in paper bags, with openings for air
  circulation
• Spread nuts in single layer on paper

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Drying Fruit

• Preparing the Fruit wash fruit and core, if
  needed
• Fruits can be halved or sliced and some left
  whole
• Thin, uniform, peeled slices dry fastest
• Apples can be cored and sliced - wedges, rings
• Bananas can be sliced
• If fruit dried whole, check or crack the skin
  to speed drying cranberries place in boiling
  then cold water to check

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Pretreating the Fruit

• Sulfuring
• Sulfite Dip
• Ascorbic Acid
• Ascorbic Acid Mixtures

• Fruit Juice Dip
• Honey Dip
• Syrup Blanching
• Steam Blanching

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Drying the Fruit

• Place fruit in single layer
• Follow directions given
• Follow approximate drying times given
• Watch food as it dries much faster at the end of
  drying period

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Determining Dryness of Fruit

• Most fruit should have 20 moisture content
  when dried
• Cut several cooled pieces in halfshould be no
  visible moisture and should not be able to
  squeeze any moisture from fruit
• Not be sticky or tacky
• If piece folded in half, shouldnt stick to itself

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After Drying

• Cool fruit 30-60 minutes before packagingdont
  pack too soon or moisture buildup could
  occurdont wait too long or could pick up
  moisture

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Conditioning Fruits

• Conditioning equalizes the moisture.
• Pack cooled fruit in plastic or glass jars, seal
  and let stand for 7-10 days
• Shake jars daily to separate pieces and check for
  moisture condensation
• If condensation, return to dehydrator for more
  dryingunless has started to mold, then dispose of

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Drying Vegetables

• Preparing the vegetables
• Wash, trim, peel, according to directions
• Uniform pieces
• Dry as soon as possible after picking

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Pretreating Vegetables

• Water blanching follow times given, start
  counting time as soon as water returns to boil.
  If takes more than 1 minute to return to boil,
  are putting in too many vegetables at a time

• Steam blanching Vegetables should be no more
  than 2 inches deep above boiling water. Cover and
  steam according to directions given for each
  vegetable

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Cooling Vegetables

• Dip briefly in cold water only long enough to
  stop cooking
• Cool to they feel only slightly hot to
  touchabout 120ºF
• Wipe vegetables and place in dehydrator

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Determining Dryness of Veggies

• Dry vegetables until brittle or crisp
• Some vegetables shatter if hit with hammer
• 10 moisture
• Dont need conditioning like fruits, as lower
  moisture content

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Fruit Leathers

• Fresh Fruit

• Canned or Frozen Fruits

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Drying Fruit Leathers

• Pour 1/8-inch thick on drying tray
• Take 6-8 hours to dry in dehydrator, up to 18 in
  oven
• Dry at 140ºF
• Dry when no indention in center of leather
• When warm, peel from plastic and roll , cool and
  rewrap roll in plastic
• Keep up to 1 month at room temp, then may freeze
  up to 1 year

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Jerky

• Lean meat like beef, pork, venison or smoked
  turkey breast
• If wild game is used, treat to kill Trichinella
  parasite by freezing a portion 6 inches or less
  thick at 0ºF at least 30 daysthis doesnt kill
  bacteria though

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Eliminating E. coli O157H7 Risk

• Heating dried jerky strips in oven after drying
  process is completed. Heat strips 10 minutes in
  oven preheated to 275ºF. Thicker strips may take
  longer heating, check temp (160ºF) with
  thermometer.

• Heating meat strips in marinade before drying
  drying times will be reduced. Check temp of
  several strips with metal stem-type thermometer
  to determine 160ºF is reached.

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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.

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Reference

• So Easy To Preserve
• Cooperative Extension Service
• The University of Georgia, 4th Edition, 1999.