Home Dehydrated Food Shelf Life
Four major factors will affect the shelf life of long term storage of home dehydrated food
Temperature affects storage shelf-life time the most. The cooler the better.
Most shelf life ratings are based on ‘room temperature’, or 72 degrees F (22 C).
Each drop of 10-degrees-C (18 F) will double the shelf life! That is pretty significant.
54 F instead of 72 F will double a 1 yr storage to 2 yrs, which may almost be the difference between storing your food upstairs in the pantry or downstairs in the basement (assuming you have a basement).
Likewise, when foods are stored in warmer temperatures, you will lose shelf life at the same proportion. 90 F instead of 72 F will halve the storage life. This fact may be more of a concern for those that don’t have a basement to conveniently store food in a cool environment.
The process of dehydrating removes most of the moisture from foods while retaining much of the nutritional value and flavor. It is a great method to preserve your harvested fruits and vegetables for later consumption off-season.
Fruits will typically contain about 75 percent moisture when fresh, and should be dehydrated to a 20 percent moisture level, the point at which they become leathery and pliable. Apparently, it is OK for fruits to be dried to this ‘pliable’ level rather than a lower ‘brittle’ moisture level because the natural sugars and acids in fruit act as an added preservative.
Vegetables must be dehydrated to a moisture level around 5 percent, the point at which they become crisp and brittle, and will break if bent.
Oxygen will interact with, and break down fats and proteins resulting in poor flavor and eventual spoilage. Fruits and vegetables only have small amounts of fat and protein but will still oxidize over a period of time when stored in an environment containing oxygen. Oxygen absorbers are commonly used inside long term food storage containers.
Photons from light will also eventually break down fats and proteins as well as vitamins in the food, resulting in poor flavor and possibly eventual spoilage.
Dehydrated Fruit and Vegetable Shelf Life
‘Shelf Life’, when referring to survival food storage, is typically defined as the maximum amount of food storage time whereby the food will not spoil and still contribute to keeping you alive.
‘Shelf Life’, when referring to grocery store and typical food packaging labels, is defined as the length of time that the food will still taste its best and retain most all of its nutritional value, usually far before actual spoilage. Having said that, shelf life is a subjective thing, and may fall somewhere in between the two extremes.
Generally speaking, home dried fruits will have a shelf life of about 6 months to 1 year, if stored in glass mason jars and in a dark, dry, and cool environment (the cooler, the better).
The shelf life of home dried vegetables vary depending on the vegetable itself and how dry they are (% moisture content), but the average number seems to be up to a year. Some claim storage life success of several years, but again, storage methods and conditions will affect storage shelf life greatly.
Also, generally speaking, the drier the food, the longer it will safely store. Vegetables should be brittle. Fruit however is not typically dried as much and remains pliable.
Store-bought dehydrated vegetables processed specifically for long term storage will be prepared, dried, and packaged in processes that bring moisture content down to as low as 3 percent, and will store much, much longer (I’ve seen claims of 25 years in #10 cans if stored properly).
My experience with home-dehydrated storage and shelf life is that 6 months to 1 year has never been a problem for us because the following growing season we are growing all new foods anyway. So as long as they last during the off-season, which is easy enough to accomplish, we’re good to go.
Vacuum Sealing, Mason Jar, or Zip Lock Bag
Vacuum sealing home-dehydrated food will add shelf life because it will remove most of the air and oxygen from the environment. Be careful though… I’ve read that there is a risk of botulism with some particular foods if they are not dried enough, and then stored in air-tight containers.
I believe that Zip Lock Bags are a decent alternative too. They take up less space than jars. I am a little leery about the effectiveness of the seal when compared to a mason jar with the nice lid. Quite often I have experienced these bags not holding a nice seal, even after ‘burping’ the bags quite efficiently. If you can smell the food while it’s zipped inside the bag, it indicates that the air is permeating through it a bit.
I personally like using mason jars because I can easily see the foods inside while on the shelf, and they are convenient and easy to handle and use.
These wide mouth 1 quart canning jars make great storage for many types of dehydrated foods that you are accessing on a semi-regular basis.
Ball Wide-Mouth Mason Canning Jar 1 Qt., Case of 12