Dehydration Temperature and Times

I am so confused. Can anyone refer me to information regarding dehydration temperatures and times so that I won’t lose the precious enzymes I’ve paid so much money to preserve. I know that grains, nuts, fruits, herbs, and veggies each have different dehydration rules. Help!!! 105 degrees takes too long, and I’m sure I could probably kick up the temperature on some of these recipes.

Comments

  • Looka here looka here! I already had this information in the box. Here’s part of an article post from www.excalibur.com

    In understanding the difference between air temp and food temp it is important to know how to read Excalibur’s dial. The temperature reading on the dial refers to FOOD temperature . In general food temperature is about 20 degrees cooler that air temp. Therefore if you set your Excalibur at 105 you are setting it to hold the food temperature at around 105 degrees, the air temperature may get as high as 125 degrees depending upon the moisture content of the food. The reason the food temperature is cooler is because of evaporation. As the moisture on the surface of the food evaporates, it cools the food keeping it about 20 F cooler than the air temperature. We have discovered this through hours of testing by measuring the air temperature and food temperature simultaneously during the dehydration process using a Doric Trendicator with type j thermal couples.

    It is also important to know how the thermostat works. We have found through experimentation, that in order preserve the enzymes, and reduce the risk of mold and bacteria, it is necessary to have a wide fluctuation in temperature. Because enzymes and microorganisms both thrive at the same temperature, we must be able to accomplish two things at once, keep the food temperature low enough not to harm the enzymes. and elevate the air temperature high enough to remove the moisture quickly to stop the growth of mold or bacteria. The wide fluctuation in temperature accomplishes just that. As the air temperature rapidly rises to its high point moisture is quickly evaporated off the surface of the food, and as the temperature lowers the dryer surface pulls moisture from the center of the food and becomes saturated again. Because of the continuous up and down fluctuation in air temperature, and constant evaporation the food temperature remains constant at a lower temperature. After all the moisture is evaporated out of the food. the food temperature will rise and then equalize somewhere in the middle of the air temperature fluctuation. Once the food temperature rises one might get worried and think that the enzymes are dead if he or she does not understand the third critical aspect. Which is, that enzymes are only susceptible to damage by high heat when they are in the wet state, therefore once the food is dehydrated the enzymes have become dormant, and can withstand much higher temperatures. According to our discussions with Viktoras Kulvinskas on this matter he said that we were right, and that, quote: “dry enzymes can survive well up to 150 deg F.” He has tested food he has prepared in his Excalibur dehydrators with an experiment he created, and found it to he high in enzymatic activity. We have also done some experiments by soaking various seeds. dehydrating them at different temperatures. and soaking them again afterwards to see if they will sprout. and they did, which proves that the enzymes are alive.

    Something that has caused us a lot of concern is we have heard so many conflicting opinions as to the temperature at which enzymes are destroyed. Twenty years ago Ann Wigmore spoke to Roger Orton personally and said that the food temperature had to go above 120 degrees for a period time before the enzymes were destroyed. Again in our discussions with Viktoras he said the same thing. Ann tested different dehydrators and found that Excalibur was the best for living foods. She found that the best technique for saving enzymes was to set Excalibur on a higher food temperature setting in the beginning and then turn it down after a few hours. However because most people may not know when to turn it down. and by leaving it on the higher setting may kill the enzymes she said to set your Excalibur on 105 degree setting throughout the entire cycle. That way the food temp will never go above 120 even after it is dry. We believe this is why many have come to believe that 105 degrees air temperature is the temperature at which the enzymes are destroyed. which is entirely inaccurate. We have also heard many people quote Dr. Edward Howell where he says in his book “Enzyme Nutrition” that prolonged temperatures over 118 F will destroy enzymes. We also read in his book where he says that the enzyme amylase can still convert starch to sugar at air temperatures up to 160 F but will wear out after a half an hour. We have also read where he says that the optimum temperatures for enzymes are 45 F to 140 F. Just recently we spoke with Dr. John Whitaker who is a world recognized enzymologist, and former dean of the Department of Nutrition and Food Science at U.C. Davis. He said that every enzyme is different and some are more stable at higher temperatures than others but that most enzymes will not become completely inactive until food temperatures exceed 140 to 158 F in a wet state.

  • beanybeeganbeanybeegan Raw Newbie

    Kendra, If the food is moist I start at 125 for 2 hours then lower the temperature to 106. Some start at 135 then lower to 106. I am waiting for all confusion to subside before I change to higher degrees. It does take a long time but that is just comparing it to cooking ovens. Dont think one meal at a time. Fill those trays for the week or more.Make a variety of patties, breads, some desserts etc and then freeze what you wont need for while. Make crackers, raw “POP CORN” and other dry items that will last with out freezing. I leave most of these items in a glass container on the kitchen counter..

    I have found that if I accidentally leave 125 on longer than should be, the food I am dehydrating, does not come out as should be. I think it is due to most recipes, are created with the idea of dehydrating at lower temperatures.

  • Thank you sooo much Beany! This is such helpful informtion. You are always guiding me along, and I appreciate you. You’re right, I gotta prepare larger quantities, but first I must get some more paraflexx sheets.

    How have you been? We haven’t talked in awhile. I think I’m addicted to this site and I havent been to the hacres.com site lately. Well, take care and we talk soon.

  • sweetpeasweetpea Raw Newbie

    I usually start at 145 then lower to 105. They use 145 at the tree of life.

  • CalebCaleb Raw Newbie

    I have actually found my Exalibur is slightly warmer than what is on the dial by 2-3 degrees. I put a thermostat inside it one day to see. So, keep that in mind. And yes dehydration takes forever. Longest I have dehydrated something so far is 36 hours :)

  • Thanks Sweetpea! I think what I’ll do for recipes that don’t specify is dehydrate at 145 degrees for 1-2 hours depending on the moisture of the food then lower to 105 degrees for the rest of the time.

    Thanks Caleb, I read that the air temperature of the Excalibur may be higher than what the dial reads, but the food will actually be at the temperature that the dial reads.

    Thanks everyone!

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