Dehydration

Dehydration is a simple process to understand - it's literally the removal of water. But understanding the different types of dehydration can benefit you in ways you may never had realized.

There are at least 4 main ways to dehydrate something.

1. Heat
Probably the most well-known method is heat. This is how most store bought food dehydrators work. This is also how clothes and hair driers work. But this method has its downside. What if the item you're dehydrating cannot tolerate heat?

2. Airflow
You can very effectively dehydrate something with nothing more than airflow. If you've ever seen carpet that was flooded, to dry out the carpet they place large fans on the carpet. Obviously you can't put the carpet into the clothes dryer, and too much direct heat could melt the fibers. So they just use air passing over the water to dry it out. This method works best if the air is dry (low humidity). If the air is already saturated with water, it won't pick up more water. Airflow is the means by which a swamp cooler works.

3. Cool
Yes, cool, the exact opposite of heat (number 1) dehydrates as well. I can't really offer a good explanation, I just know that it does. By far the best lesson to be learned here is bread. A lot of people buy a loaf of bread and when they get home they put the loaf into the fridge to keep it from spoiling. The problem is the cool air of the fridge dehydrates the bread and makes it stale. You're better off leaving the bread on the counter in an airtight container. Of course, if left out too long (days or weeks) it will eventually grow mold. If you need long term storage put the bread into your freezer. "But wait, you said cold dehydrates, so why put it into the freezer?" Well I actually said "cool" dehydrates, not cold. The thing with the freezer is the temperature is so cold that the moisture in the bread turns to ice before it can evaporate into the air. So the short take home lesson, leave bread in a sealed container on the counter, or in a sealed container in the freezer, but never in the fridge.

4. Absorption
The final way to dehydrate is through absorption. Obviously you can use cloth and paper towels to absorb water. But you can also use substances to dry out the air which in turn dries out the "wet" object. Have you even opened something you just bought and inside was this small paper bag full of little beads? That's called a desiccant, which is just a hygroscopic substance. Hygroscopic is just a fancy work meaning it absorbs water. Common hygroscopic substances include paper fibers, sugar, honey, and table salt. Another really good hygroscopic substance is uncooked rice. If you ever drop your cell phone or other small electronic device into water, place it into a ziplock baggie filled with rice. The rice will absorb the moisture out of the device and hopefully save it from destruction.

Well there you go, 4 different ways to dehydrate something.