Drying Food Tips

When you dry foods, remember the following:

• It is very important to know that drying process must not be interrupted. Once you start drying the food, don't let it cool down in order to start drying again later because mold and other spoilage organisms can grow very quickly on partly dried food.
• Trays, screens or racks need to be safe for contact with food. Do not use screens made from copper because copper destroys vitamin C and increases oxidation. Avoid screens made from aluminum because they tends to corrode and discolor.
• Fruits and vegetables must be prepared for drying as soon as possible after harvesting.
• Cleanliness and safety are very important throughout the drying process.
• It is very important to cut food into uniformly-sized pieces for the best result.
  
• If you are drying juicy fruits such as apricots, cut them in half, remove the pits and set the pieces on the racks with the cut side up. This way the flavorful juices will not drain out and be lost.
• If the climate in your country is humid use an oven or food dehydrator.
• Keep in mind that heat is not the same in all parts of the oven or dryer and stirring the pieces of food frequently and shifting the racks in the oven or dryer are essential for uniform drying.
• To speed the drying process you can increase only the air flow (not temperature).
• Remember that lighter load dries faster than a full load.
• For the first part of the drying process, the air temperature can be relatively high (because food is cold), that is about 150° to 160° F (65° to 70° C), so that moisture can evaporate quickly from the food. Watch the process very carefully, and as soon as surface moisture is lost (the outside begins to feel dry), the air temperature must then be reduced to about 140° F (60 °C).
• Use a thermometer to check the oven temperature to make sure it stays at 140° F. Check the temperature about every half hour, because it is very important to keep the oven temperature at 140 degrees F.
• If you use higher temperatures to long the food will cook instead of drying. If the food cooks on the outside and the moisture cannot escape the food may harden on the surface and the food will eventually mold.
  
• If the temperature is too low at the beginning, the food may undergo undesirable micro biological changes before it dries adequately.
  
• Some food needs to be turned over occasionally for successful drying.
• Stirring occasionally prevent foods from sticking to the trays and also helps the food to dry evenly.
• It is very important to watch whole drying process carefully, because toward the end of the drying process the food can scorch easily (each fruit and vegetable has a critical temperature above which a scorched taste develops).
• Do not keep adding fresh produce to the dehydrator as the food is drying. This common practice increases the time required to reach an acceptable degree of dryness and will produce a poor quality product.
  
• Never use the broiler unit of an electric oven because the food on the top tray will dry too quickly. The best solution for oven drying is a proper model of convection oven that has a timer and controllable temperature starting at 120 degrees F.
• If you have only two oven racks and want to stack more trays in the oven you can use blocks of wood and put them in the corners of the racks to hold the trays at least 2 inches apart. Dry no more than four trays of food at a time.