silica or calcium chloride to keep food dry?
what is a food grade desiccant?
To start off, one has to know that desiccant is a substance which absorbs water, and that it is usually used to help products stay dry and not fall to moisture degradation. There are several famous desiccants, among which is calcium chloride, salt, rice, silica gel, etc. All of these are great at collecting water, and are used commonly everywhere. Silica gel is great for protecting flowers and drying them out, but there are some types of silica gel which contain cobalt chloride and are therefore unsafe for the environment and food storage.
One can get a food grade desiccant almost everywhere. Food grade desiccants are good for pest control, but keep in mind that pool grade desiccants should not be placed around your home, as they are heat treated. This means that silicon dioxide converts to crystalline silica, a very dangerous and harmful abrasive to a human’s respiratory system, which causes a certain and progressive lung disease silicosis.
Silica gel is non-toxic and GRAS recognized product, which meets FDA requirements. Therefore, it is safe to be used in house environments.
calcium chloride keeps food driest
There have been several tests to confirm which desiccant is the best, and so far, nothing can keep up with calcium chloride. In one test, one cup of calcium chloride picked up 125 grams of water in just 40 days. It doubled in volume and gained an outstanding 56%.
First runner up was the non-dairy creamer, which picked up 20 grams of water and increased by 16%. Other desiccants used (silica gel, rice, salt) didn’t do very good, and their mass didn’t change significantly. Silica gel started with a weight of 225 grams, and ended with the same weight. This is in a 40 days period, and I`m sure that a 365 days period would be a different story.
what makes calcium chloride superior to silica gel?
It all comes down to these two, which are the best at collecting moisture from their environment. Calcium chloride dissolves partially into a liquid brine for its structure allows it to attract its own weight in water multiplied by several times. On the other hand, silica gel remains dry at its full absorb capacity. The reason is simple: silica gel can, in optimal conditions, absorb only around 40% of its weight in water.
Calcium chloride will stay contained even in liquid form. If you are creative enough, you can easily create your own packets, using coffee filters and calcium chloride. You can also buy ready ones online, which are very similar to silica gel packages.
Calcium chloride keeps the water absorbed protected for a long period of time, while silica gel absorbs water into microscopic pores, which can cause spikes in humidity during voyage. In the end, calcium chloride is safe for environment, since it is a naturally occurring compound found in abundance in seawater. It is non-toxic, and can be disposed with regular wastewater. Many silica gels, on the other hand, contain cobalt compounds, which are known to be carcinogenic, and the disposal of is done using special hazardous waste procedures.