I recently received the following question. “Just beginning to do some food storage. I live in sunny BUT humid central Florida. We often have 80-90 percent humidity outside. We do have central air but concerned about repacking staples into Mylar, Mason jars and plastic juice/soda bottles. Would you recommend using the desiccant packs? I am not concerned about after it is repackaged (have a nice dark, dry closet) just figuring that getting it in the packaging might expose it to too much moisture to begin with”.
This is a good question and one I have seen come up regularly. While it has always been my opinion that this is not too much of a problem if the grain or beans are kept dry, since I live in a fairly dry climate, I have done some additional research on the subject.
The LDS Church says that as long as the moisture content is less than 10%, it is not a problem. See the warning that they have on their website. “Warning: Botulism poisoning may result if moist products are stored in packaging that reduces oxygen. When stored in airtight containers with oxygen absorbers, products must be dry (about 10% or less moisture content).”
That being said, they do not use desiccant packs in there canneries even in Florida. It is relatively easy to determine roughly the percentage of moisture in your grains and beans. Use the test suggested in the following article The effects of Temperature and Moisture on Stored Grains. Check the source of your products and make sure you are buying low moisture products and not something that has been sitting outside in the rain.
Another factor is that Oxygen absorbers require a small amount of moisture to work; desiccants may stop them from functioning. None of the food storage companies use them in long-term dry storage foods.
Sorbent Systems a major distributor of food storage supplies says the following
“ If you are concerned about humidity affecting your food product? (rice, wheat, beans and other dry grains…..)
We have a clearly established protocol and procedure for providing a solution to this problem.
One to two individual 1 oz. packets of desiccant should be placed in the bottom of your MylarFoil™ bag prior to filling with product. The oxygen absorber is then placed on top for sealing. Note: This is the recommended procedure for the 20.0″ x 30.0″ bag (P/N: 20MFS30) that is designed for 5 and 6 gallon pails.”
Hope this answers your question.