Determining the storage life of foods is at best an inexact science as there are so many variables. These range from the condition your food was in when you first purchased it and includes many other factors. This page was written with input by Mr. Stephen Portela who has over 30 years of professional food storage experience. This information should be used as a general guide only, and should not be followed “as the gospel truth” because your results may be different.
Four Factors that affect food storage:
Factor #1: The Temperature:
Temperature has more to do with how long well dried foods store than anything else. The USDA states, “Each 5.6 C. (10.08F) drop in temperature doubles the storage life of the seeds.” Obviously, there is a limit as to how far this statement can be taken. However I expect it basically holds true from room temperature down to freezing. No doubt, the inverse could also be considered true. “Each 5.6C. (10.08F) rise in temperature halves the storage life of seeds.” This theory holds true for non-garden seeds as well.
Storage Life Differences
Depending on Temperature
Constant Storage: Storage life Temp in degrees F In Years —————- ———— 39.76 – - – 40 49.84 – - – 30 59.92 – - – 20 70.00 – - – 10 80.08 – - – 5 90.16 – - – 2.5 100.24 – - 1.25
Note: the above chart is not for a specific food but shows the relationship between temperature and storage life.
Let’s look at a couple of real life examples of good and poor food storage practices:
About a year ago we got an unopened paper bag of white flour which had been stored at 70 degrees F, in a dry climate. It had been sitting for 3 years in a closet. It made fine looking bread but had such an ‘old’ and bad flavor that it was difficult to eat. For another example, a couple of years ago in the Puget Sound area we were given a 4 gallon can of wheat that had been stored up high in a garage for about 30 years. This part of the country is not as hot as some places, yet in the summers the average garage still gets up into the 90′s. Even though wheat will store for 30+ years under good conditions, the bread from this particular wheat was very bad tasting and after a few batches we ended up throwing the wheat away (something I always dislike doing).