America’s Leading Water Damage Restoration & Mold Remediation Company.

Damp Solving Water Damage Restoration & Mold Remediation

Call Today

All States Covered

USA

Rice Absorb Moisture

Home / Blog

Does Rice Actually Absorb Water?

Besides its rich nutritional value, there is a common conception that rice can also be used as a moisture absorber and drying agent.

If you’ve never heard of that, there’s a good chance you’ve heard someone recommend rice as a remedy for wet cell phones and electronic devices.

In other words, if after accidentally soaking your cell phone, camera, or charger in water, there is a good chance that you will find someone, either a family member, friend or someone on the web, recommending to put the device in a bowl of uncooked rice and leave it there for at least 24 hours.

So, is rice really a water absorber?  Can it really be used to absorb water and moisture?  And can we rely on it to regulate humidity levels in our buildings and rooms?

That’s what we attempt to tackle as you read further down the page.

TLDR; (Too Long, Didn’t Read!)

Rice is hygroscopic and therefore can be used to absorb moisture, especially in tight areas and closed boxes.  However, rice is not the ideal solution for drying large rooms as it will take enormous quantities to get satisfactory results.

 

Can Rice Soak Up Water?

The short and confident answer is yes, RICE CAN ABSORB WATER. 

like most grains, rice is hygroscopic.  What does hygroscopic mean?  It means that it can absorb and attract surrounding water molecules, and in doing so, it makes nearby objects drier and less humid.

However, what differentiates rice from many other hygroscopic products is that rice is not deliquescent.

A deliquescent material can also absorb water.  However, it keeps doing it until it dissolves again in that water and becomes leaky.

A deliquescent is therefore not an ideal water absorber since once it dissolves, it releases all the water it has acquired and unleashes it back into the environment from which it comes.

Rice is not deliquescent and therefore does not dissolve in the water it absorbs.  Instead, the attracted water molecules simply build upon the grains and do not liquefy.

Ever wondered why cooked grains of rice seem bigger than uncooked ones?  Well, it’s water that makes that size difference.

 

Can We Use Rice To Absorb Moisture And Water?

Now that we know that rice can absorb water, it’s time to answer the question we’re here for today:  Can rice be used to absorb moisture?

Well, with everything we said in the previous section, it is very important to note that the water that rice absorbs does not stay on the grains forever.

Just as rice can gain water, it can also lose it and make surrounding objects more humid.

That’s what we call water desorption.

Typically, rice absorbs water when the surrounding environment is humid and desorbs water when the surrounding environment is dry.

Why does this happen?  Well, in simple words, water vapor is always in search of pressure balance.

This means that water molecules are always migrating from a high-pressure environment to a lower pressure environment.

In more complex terms, if there is water vapor in two adjacent unsealed environments, the two environments will continue to exchange water molecules until the vapor pressures in the two environments are the same.

Likewise, when rice is put into a room, it will continue to exchange water with the air until the vapor pressure in the air becomes equal to the vapor pressure in the rice grains.

So this answers whether rice can be used to absorb moisture or not.

I mean, it all depends on the amount of humidity in the room where you put the rice.

If the room is damp and has high humidity levels, then yes, the rice will absorb moisture and help reduce humidity in that room.

If, on the other hand, you put the rice in a dry room, you might be shooting yourself in the foot, because if the rice has a high moisture content, it can release water vapor into the air and make the room more humid.

How Much Rice Do We Need To Absorb Moisture?

Everything we have talked about so far is purely theoretical and only explains what science says about the hydroscopic properties of rice.

Now, if we want to enter the practical world, we will be forced to ask a very important question.  How much rice does it take for our moisture absorption purposes?

Remember that rice will only absorb moisture when the vapor pressure inside the grains is lower than what there is outside.

Once we reach the pressure equilibrium, the rice will stop attracting water and the ambient humidity will stay at the same level unless you add more rice with lower vapor pressure.

Additionally, despite its hygroscopic properties, rice has also a hard seed shell, and therefore, it will require direct contact with water in order to absorb much if it in the most efficient manner.

This probably explains why putting a wet cell phone in a bowl of rice doesn’t work all the time.

The rice helps to absorb some of the moisture from the device, but it can;t dry it out completely since there isn’t direct contact with all the water inside.

Anyway, all of this suggests that, in fact, rice will only be effective if we apply it to small areas with small moisture issues.

Here, yes, even a small amount of rice will work well and help absorb moisture in the problematic (and small) area.

If, however, you want to make rice the moisture controller in your house and residential rooms, then I’m afraid that you will need a huge amount of it in order to notice any satisfactory results.

Yes, you’ve guessed right.  This is not very practical.  Unless you are okay turning your house into a rice storage facility!

 

Is Rice The Ideal Water Absorber Solution?

Well, after we have just said, it’s clear that the answer depends on where you want to put the rice.

If you simply want to dry your cupboard, closet, drawer, or any small box in which you put goods that must remain damp free.  Then yes, rice can be a great choice for that.

Just be sure to renew the rice now and then in order to create a new imbalance and reduce humidity even further.

Another way around would be to dry the rice in the oven for a few minutes before putting it back in the box again.

Now, if on the other hand, you want to reduce the dampness of an entire room, then rice is probably not the perfect solution for that.

First, and like we said, you will need enormous quantities of rice to see any noticeable difference in moisture levels.

Not something everyone can afford and let’s face it, not practical!

Second, rice can become counterproductive if the relative humidity drops.

As we mentioned before, if the rice has more moisture than the surrounding air, it will start to give off water, making the surrounding air wetter and more humid.

On top of that, you can’t control how much rice you need to bring the humidity level to an optimal, safe, and comfortable level.

If you put too much rice in a room, there is a risk that the relative humidity will drop too much and this can decrease your comfort and even be dangerous for your health.

Symptoms like cracked skin, itchy eyes, and increased sensitivity to allergens and respiratory infections can all be the byproduct of too low humidity.

The lack of moisture in the air can also cause decorative arts, wooden furniture, and building matters to deteriorate and shrink.

Cooked Or Uncooked Rice?

If you are to use rice as a drying agent, be sure to use it when not yet cooked as it is more likely to have less moisture and will help absorb more moisture.

Cooked rice is usually already saturated with water and can therefore give off more moisture into the space you want to dry.

Alternatives To Rice When Absorbing Water Or Moisture?

the following substances and matters are also hygroscopic and non-deliquescent.

They are therefore similar to rice in terms of moisture absorption and humidity control.

  • Honey
  • Silica Gel
  • Deciccants
  • Nylon
  • Germinating Seeds
  • Hesperostipa Comata Seeds
  • Baking Soda
  • Aluminum Oxide
  • Molecular Sieve

 

 

pouring water into rice in a bowl

25 Years of Experience

We Tackle Water Damage & Mold Remediation In Your Area.

 

Water Damage Restoration

Mold Remediation

Wow, this really worked, thanks!

J. Sullivan – New Orleans