Drying Foods


Published on

Susan Shockey, PhD, of the OSU Extension-Franklin County, discusses the basics of drying various fruits and vegetables.

Published in: Self Improvement
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide
  • 3. In order for food to be safe, we must understand and follow guidelines to make sure that the method we practice will be safe for our families
  • 1. When moisture is removed, bacteria, yeast and mold cannot grow and cause the food to spoil 2. Drying also slows down the action of enzymes (natural substances that cause foods to ripen), but it does not stop them totally Other: Some foods may be hydrated before using, like vegetables or soups or beans Others like fruit leathers or banana chips are a great snack just the way they are Low humidity aids the drying process Ohio weather is not always the best for drying foods, most all the time we would need to use equipment to dry our foods and not count on outside condidtions like they can in some parts of the county
  • 1. In this area sun or solar drying is not recommended, for best results the oven or dehydrator 2. Vine drying might be used here for beans—leave them in the pod on the vine in the garden until the beans rattle inside When the vines and pods are dry and shriveled, pick the beans and shell them If the beans are still moist, the drying process is not complete and the beans will mold if not dried in the oven or dehydrator If beans are vine dried totally, they will still need to be sterilized for safe use- you can do this in one of two ways: Freezer method- place food in bags and leave in freezer for at least 48 hours Oven method – place food in single layer in a shallow pan in the oven at 160 degrees for 30 minutes
  • 2. Because most of us have an oven, we can use it to try out the process and not need to purchase any additional equipment 3. Because many use the oven on a daily basis, the long drying time might be hard to work around mealtime schedules in the kitchen 4. A conventional oven doesn’t have a fan to help circulate the air like a convection oven might – that would make them a better choice or may also place a fan near open door to help improve the air circulation But because of the process it takes twice as long to dry foods in the oven than in the dehydrator If you have a choice, choose a low humidity day to try it out 5. Use a low setting 140 degrees – if your oven doesn’t go this low it may cook the food instead of drying it and for air circulation leave the oven door propped open 2 to 6 inches This will cause the temperature to vary, use an oven thermometer to give an accurate reading Trays used should allow 3-4 inches on all sides for air movement and trays should be 2-3 inches apart for best circulation—may try baking cooling racks on top of cookie sheets Food dried in the oven is usually darker, more brittle, and less flavorful If you have small children-this may not be a good option to have them around on open oven door
  • 1. Dehydrators are designed to dry foods efficiently at 140 degrees May range in cost from $35-300 depending on the features and number of extra trays purchased 12 square feet dries about a half bushel of produce - major disadvantage of a dehydrator- its size and small capacity There are two types of dehydrators: horizontal and vertical The horizontal air flow has the heating element and fan that are located on the side of the unit This design reduces flavor mixture so several different foods can be dried at one time and all trays receive equal heat The juices or liquids don’t drip down on the heating element- making a messy clean up The vertical air flow have the heating element and fan located at the base This means that if: Different foods are dried, the flavors can mix Liquids can drip onto the heating elements
  • 1. In general we need to make sure that we purchase or select produce in good condition, without blemish and ready to eat, not over ripe Wash the item well and allow to drain 3. & 4. Remember that small even pieces will dry more evenly and better than whole pieces or irregular sized pieces 5. We want our food to look good after the process so we need to choose a pre-treatment to keep it looking and tasting good- more to come 6. & 7. Allow pieces to be in a single layer, not touching so that air can more around each one to dry effectively
  • Pretreatments The goal is to keep fruit from turning dark when they are exposed to air For many years sulfuring was the only method used For some people with allergies or asthma, the sulfites found in the food have been found to cause asthmatic reactions Thus there are other choices 2. Sulfuring: is an old method where sublimed sulfur is ignited and burned in an enclosed box with the fruit Probably not the method most of us would choose, but effective Must be done outdoors where there is adequate air circulation DIRECTIONS: Using a sulfite dip can achieve the same long term effect, but more quickly and easily Either sodium bisulfite, sodium sulfite or sodium meta-bisulfite that are USP (food grade) or Reagant grade (pure) can be used Check local drugstores, hobby shops where wine making supplies are sold 3. Ascorbic Acid : otherwise known as vitamin C mixed with water is a safe way to prevent browning But, it’s protection doesn’t last as long as the above method Can be purchased in tablet form to dissolve in water for soaking, then drain before placing on dryer trays Ascorbic Acid mixtures are available, but are not as effective as using pure ascorbic acid and they are more expensive 4. Fruit Juice Dip : is using a fruit juice that is high in vitamin C like orange, lemon, pineapple, grape and cranberry through not as effective as the pure ascorbic acid, each juice adds its own color and flavor to the fruit Fruit is soaked in the juice and then drained 5. Honey Dip : while effective against darkening, realize that you are adding calories This dip is made of sugar, water and honey Let fruit soak 3-5 minutes, then drain 6. Syrup blanching : the resulting product is similar to candied fruit Best used with apples, apricots, figs, nectarines, peaches, pears, plums and prunes Use corn syrup and water and bring to a boil- let simmer 10 minutes and let stand for 30 minutes before draining and placing on dryer trays 7. Steam Blanching : changes the flavor and texture of the fruits, check chart for times Other : Peel can be left on the fruit, but takes longer to dry (apples) If choosing to do whole fruits with skins place in boiling water, then in cold water to crack the skin- and speed the drying process Spray the trays well because of the sugar content in fruit, will be sticky After drying for 2-3 hours, may need to turn each piece with a spatula
  • 1. Vegetables contain less acid that fruits Vegetables are dried until they are brittle Keep pieces uniform in size so that they will dry evenly Prepare only as many as can be dried at one time 2. Blanching is the process of heating vegetables to a temperature high enough to destroy enzymes present in the tissue This helps to preserve the color and flavor during drying and storage Water blanched Water blanching- bring water in a large pot to a boil, place vegetables in wire basket or a colander and submerge them in the water Cover and blanch according to directions Begin timing when water returns to a boil If, it takes longer than one minute to come back to boiling, too many vegetables were added, use smaller amounts next time Water blanching usually is quicker, but results in greater nutrient loss than steam blanching Steam blanched Steam blanching is done with a deep pot with a tight fitting lid and a wire basket, colander or sieve placed sot the steam will circulate freely around the vegetables Bring to a boil and place no more than 2 inches of vegetables in the basket Cover and steam according to directions After blanching, dip briefly in cold water Wipe excess water off and arrange in a single layer on the tray They don’t have to be cool, the heat left in the vegetables from blanching will cause the drying process to begin more quickly Watch them closely at the end of the drying time recommended so that they don’t scorch
  • 2. Package and store—vegetables don’t need to condition like fruits because of the lower moisture level Glass jars, metal cans or freezer containers are good storage containers if they have tight fitting lids Plastic freezer bags can work, but they are not insect and rodent proof 4. Can be stored up to a year in cool temps (60 degrees), or only 6 months at 80 degrees Dried vegetables have about half the self life of fruits Fruit leathers keep up to one month at room temperature If you want to store any items longer, keep it in the freezer 5. Conditioning is when you allow fruit to stand for 7-10 days, shake daily and check for moisture condensation!! Very important If condensation develops in the jar, return the fruit to the dehydrator for more drying Fruit that has been sulfured or sulfited should not touch the metal, place it in a bag first before storing in the metal can
  • 2. If using items in soups and stews, no need to re-hydrate prior to adding to the recipe, they will hydrate as they cook May need to add additional liquid When re-hydrating fruits and vegetables, refer to the chart to see how much water (or liquid) is added and how long before use they need to soak Most times vary from 30 minutes up to two hours before using Be careful not to over soak items to prevent loss of flavor and a mushy, water-logged texture
  • Because of the concern with e-coli there are special considerations needed before drying jerky at home If you choose to use raw meat to dry realize that salmonella and e-coli are not destroyed during the drying process Current recommendations are to pre-cook meat before drying, but the final product is hard on the outside surface Use only lean meats in excellent condition Remove fat, gristle and connective tissue Fat becomes rancid quickly and causes off flavors during drying or storage For that reason, highly marbled meats don’t work well either Slice meat in thin strips 1/8 to ¼ inch thick and 1 to 1 and ½ inches wide, 4- 10 inches long If chewy jerky is preferred, cut with the grain of the meat, if more tender cut across the grain Lay them on a single layer cookie sheet and flatten with a rolling pin so they are fairly even in thickness Always wash and sanitize cutting boards, utensils and counter tops with hot soapy water and sanitize with 1 teaspoon bleach per quart of water to make a sanitizing solution One safety measure to prevent e-coli is to pre-cook meat before drying to 160 degrees, it does change the quality and may be different than your expectations Marinades are also helpful in reducing bacteria Marinate 1 to 24 hours, then begin drying immediately For 10-14 hours or until the pieces are adequately dry Test for dryness—should be like a green stick, not snap like a dry stick Place in bag or jar with a tight fitting lid Pack jerky with the least possible amount of air trapped in the container Store for best results in the refrigerator or freezer Will keep 3-6 months in refrigerator or up to one year in the freezer Check occasionally for mold, if found, dispose of item
  • Drying foods can help preserve items that you might not traditionally choose to preserve Try a couple of your favorites and evaluate to see if they meet your expectations and remember to: 1. Use up to date information and current recipes 2. Make sure you have the needed equipment to save you time and money 3. Use fresh quality, prime produce 4. & 5. Keep a clean environment and follow instructions carefully
  • Drying Foods

    1. 1. Simple, Safe, Easy to Learn Drying Foods
    2. 2. Today’s Topics <ul><li>Understand how drying process preserves foods </li></ul><ul><li>Review what equipment is needed </li></ul><ul><li>Learn how to choose best methods of treating fruits before drying </li></ul><ul><li>Understand how to blanch vegetables before drying </li></ul><ul><li>Learn how to safely store dried foods </li></ul>
    3. 3. How Does Drying Foods Work? <ul><li>Removes moisture from food so that bacteria, yeasts, and molds cannot grow </li></ul><ul><li>Drying also slows the action of enzymes, but does not kill them </li></ul>
    4. 4. Methods of Drying <ul><li>Sun or Solar Drying </li></ul><ul><li>Vine Drying </li></ul>
    5. 5. Methods of Drying <ul><li>Oven Drying </li></ul><ul><ul><li>Great to use if trying out the process </li></ul></ul><ul><ul><li>Challenging because of daily use </li></ul></ul><ul><ul><ul><li>Hazard for small children </li></ul></ul></ul><ul><ul><li>Slower than dehydrators – no air movement </li></ul></ul><ul><ul><ul><li>Food is darker, less flavorful </li></ul></ul></ul><ul><ul><li>Uses more energy </li></ul></ul><ul><ul><ul><li>Cost more </li></ul></ul></ul>
    6. 6. Methods of Drying <ul><li>Electric Dehydrator </li></ul><ul><ul><li>Double wall construction-metal or plastic </li></ul></ul><ul><ul><li>Enclosed heating elements </li></ul></ul><ul><ul><li>Enclosed thermostat with dial control </li></ul></ul><ul><ul><ul><li>From 85 to 160 degrees </li></ul></ul></ul><ul><ul><ul><ul><li>Timer </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Fan or blower </li></ul></ul></ul></ul><ul><ul><ul><ul><li>4-10 open mesh trays-easy wash plastic </li></ul></ul></ul></ul><ul><ul><ul><ul><li>UL seal of approval </li></ul></ul></ul></ul>
    7. 7. Methods of Drying <ul><li>Microwave </li></ul><ul><ul><li>Fast way to dry herbs when in small quantities </li></ul></ul><ul><ul><li>Follow MW directions </li></ul></ul><ul><ul><li>Do not use for other food items- moisture doesn’t evaporate </li></ul></ul>
    8. 8. Preparation of Food <ul><li>Select high quality produce </li></ul><ul><li>Wash and core </li></ul><ul><li>Leave whole, half, or slice in equal pieces </li></ul><ul><ul><li>Smaller is better </li></ul></ul><ul><li>Select appropriate pretreatment </li></ul><ul><li>Place in single layer on drying trays </li></ul><ul><li>Pieces should not touch or overlap </li></ul><ul><li>Follow directions for your method </li></ul>
    9. 9. Pretreatments <ul><li>Fruit </li></ul><ul><ul><li>Sulfuring </li></ul></ul><ul><ul><li>Ascorbic Acid </li></ul></ul><ul><ul><li>Fruit Juice Dip </li></ul></ul><ul><ul><li>Honey Dip </li></ul></ul><ul><ul><li>Syrup Blanching </li></ul></ul><ul><ul><li>Steam Blanching </li></ul></ul>
    10. 10. Pretreatments <ul><li>Vegetables: </li></ul><ul><ul><li>Blanching – Water or Steam? </li></ul></ul><ul><ul><ul><li>Hot water, colander, ice water, drain </li></ul></ul></ul>
    11. 11. Testing for Dryness <ul><ul><li>Vegetables </li></ul></ul><ul><ul><ul><li>Brittle </li></ul></ul></ul><ul><ul><ul><li>Flake when crushed </li></ul></ul></ul><ul><ul><li>Fruit </li></ul></ul><ul><ul><ul><li>No visible moisture </li></ul></ul></ul><ul><ul><ul><li>Pliable, but not sticky or tacky </li></ul></ul></ul><ul><ul><ul><li>Folded in half-doesn’t stick to itself </li></ul></ul></ul><ul><ul><ul><li>Berries should rattle </li></ul></ul></ul>
    12. 12. Packaging and Storing <ul><li>Cool 30-60 minutes </li></ul><ul><li>Pack loosely in plastic or glass jars </li></ul><ul><li>Seal containers tightly </li></ul><ul><li>Store in cool, dark place </li></ul><ul><li>Dried fruit needs conditioning- </li></ul><ul><ul><li>Pack loosely in plastic or glass jars </li></ul></ul><ul><ul><ul><li>Shake daily </li></ul></ul></ul>
    13. 13. How Should I Use Them? <ul><li>Snacks: dried fruits </li></ul><ul><li>Dried vegetables are good in soups, casseroles, easy to re-hydrate </li></ul><ul><li>Both are good to store as emergency food </li></ul>
    14. 14. Drying Meats <ul><li>Meats should be stored in the freezer </li></ul><ul><li>Precook meat before drying </li></ul>
    15. 15. Summary <ul><li>Use up to date information and recipes </li></ul><ul><li>Collect and inspect needed equipment </li></ul><ul><li>Use fresh produce </li></ul><ul><li>Make sure equipment and kitchen are sanitary </li></ul><ul><li>Follow instructions carefully </li></ul><ul><li>Enjoy </li></ul>
    16. 16. Questions? <ul><li>“ This material has not been peer-reviewed for statewide distribution -- blind peer review pending.”   </li></ul>
    17. 17. References: <ul><li>Andress, E., & Harrison,J (2006) So Easy to Preserve 5 th ed.). Cooperative Extension, The University of Georgia </li></ul><ul><li>Kendall,P.,DiPersio, P & Sofos, J. Drying Vegetables, bulletin no 9.308, University of Colorado </li></ul><ul><li>Kendall,P, Dipersio, P. & Sofos, J. Drying Fruits, bulletin no 9.309, University of Colorado </li></ul>