Media Workers and TV Researchers - Please seek permission before posting on this site or approaching individuals found here by phone or email - write to the Editor - mail to nick@off-grid.net


Home Forums Technical Discussion Freeze drying food Re: Freeze drying food

#66353

I have been freeze drying food for about 4 months now. I’m using a normal deep freeze for freezing the sample. I have a flexi-dry lab freeze dryer to use as a cold sink to trap the moisture. I use a rotary vane vacuum pump.

The process is very simple if you are freezing items that you would normally freeze, (ie items that don’t break down from large ice crystal formation)like hamburger, fried potatoes, pork, beef, chicken, etc. Basically you freeze the item, then apply a vaccum less than 6 mbar and let the food come to room temperature or the temperature of your heat source. I use 8 incandescent 100 watt bulbs as a heat source.

I use mason quart jars as my vacuum dry vessels. I dry 6 jars at a time and they normally take 24 hours, depending on the consistency of the food item.

It is a great system for saving left-overs.

If you want to dry high sugar items like fruits or you want to retain the structure of high moisture items like green peppers you will need a colder freeze, at least -30 degrees C.