Do You Need a Guitar Humidifier? Here’s What You Need to Know About Humidity and Guitars


It’s that time of year.  Both on your classical guitar and off.  Guitar humidifier ready?

The leaves are changing color, fall fashion is in full swing, and people can’t get enough of those pumpkin-spiced beverages.

While all that is happening outside, there are also changes inside our home.  The temperature may be cooler.  We start putting on the heater, and the air feels a bit dryer.  This all affects the humidity in our homes.

In this article, we’ll explore how much of a problem – or not – this can be for our guitars.

Table of Contents

What is Humidity?

Humidity refers to the amount of water vapor in the air.

Wood, the primary material in guitars, is hygroscopic, meaning it absorbs and releases moisture. This can cause the wood to expand or contract, leading to issues like cracking, warping, or swelling.

Maintaining balanced humidity is key to preserving your guitar’s longevity and sound.

It’s not good for the different woods inside our guitars to get too dry.  So we may need to humidify our instrument in the dry cold of winter or the hot dryness of summer.

How to Spot When Your Guitar is Thirsty

For most guitars, the first sign of dryness is often when a squeak or a noise appears that wasn’t there before. Maybe a string or two mysteriously pops when the guitar isn’t being used.

Another sign can be when the ends of the frets seem sharp on either side of the fretboard.  This is because the neck may have shrunk slightly.  We might also find a slight gap between the bridge and the guitar top.

In an extreme case, the wood can crack, or the glue can fail.  So if we’re concerned, the secret is not to let our beloved guitars get into that situation.

How to Deal with Humidity for Guitar Maintenance

The first thing to do is gauge our level of worry.  If we have a “beater” guitar or an instrument that we are not concerned about, then we don’t need to worry too much about humidity.

However, if we are playing an instrument that we really value, then we may want to consider the humidity level, particularly where we store the instrument.

Here comes the science:

Room Temperature Levels

The best room temperature at which to store our instruments is around 70 to 76 degrees Fahrenheit (21 to 24 C).

Relative Humidity Levels

Relative humidity is the percentage of water vapor in the air.  Many luthiers recommend keeping our instruments stored at around 45% to 55% relative humidity.

Traveling

If we’re traveling, we need to keep an eye on humidity changes.  We can use a humidity system in our case (see below).  It’s also a good idea to check if our guitar case has a rubber seal to keep moisture in and heat out.

Too Much Science?

If this all sounds like far too complicated, don’t worry.  There are easy ways to control the humidity around our guitars.

Many experts recommend using a device soaked with water that sits in between the strings of the guitar.  This allows it to provide direct moisture to the wood inside your guitar as it evaporates naturally.

Several manufacturers supply different designs of these, including:

And many modern digital humidifiers can be set to monitor themselves inside the home.  

Types of Humidifiers for Guitar

We have three main types of humidifiers to choose from.  And while each has pros and cons, any will work fine to keep your guitar well-watered.

In-Case Humidifiers: These are placed directly in the guitar case, offering a controlled environment. They’re ideal for individual guitars but require regular monitoring.

Soundhole Humidifiers: Inserted into the guitar’s soundhole, these are great for direct humidification but must be used cautiously to avoid over-humidification (i.e. dripping water into your guitar).

Room Humidifiers: These control the humidity of the entire room, beneficial if you have multiple instruments. However, they can be more expensive and require space.

DIY Guitar Humidifiers

Even better, we can make our own guitar humidifiers cheaply and easily out of a baggy and a paper towel!

Just put a damp (not dripping) paper towel in a loosely rolled sandwich bag.  Then put this in your guitar case.  Easy as pie.

Or, to humidify a whole room, we can place or hang a pot of water on a radiator or heater.

Pots sold exactly for this purpose can often be bought from garden centers, florists, or stores selling house plants.  Mother Nature likes a bit of moisture in the air, too.  And our guitar was once a tree, after all.

Or, there are many humidifiers available commercially.

Common Concern: “Can’t a Guitar Humidifier Cause Mold?”

Yes, in extreme cases, added humidity can cause mold.  This is why it is important to understand humidity levels.

Unwanted mold usually forms above 60% humidity.  Guitars like 45% to 55%.  So if we set the digital humidifier to 50%, we should hit the sweet spot.

Mold in guitars is very rare, but it could happen.  More often, the opposite is the concern.

If you are nervous about that, buying a hygrometer is a great way to know that your humidifier is properly calibrated.

Additional Tips for Guitar Care in Varying Climates

In dry climates, humidification is more critical, while in humid climates, dehumidification might be necessary.

In seasonal changes, adjust your humidification approach accordingly.

For long-term storage, ensure your guitar is in a stable, humidity-controlled environment.


Allen Mathews

Hi, I’m Allen Mathews. 


I started as a folk guitarist, then fell in love with classical guitar in my 20’s. Despite a lot of practice and schooling, I still couldn’t get my music to flow well. I struggled with excess tension. My music sounded forced. And my hands and body were often sore. I got frustrated, and couldn’t see the way forward. Then, over the next decade, I studied with two other stellar teachers – one focused on the technical movements, and one on the musical (he was a concert pianist). In time, I came to discover a new set of formulas and movements. These brought new life and vitality to my practice. Now I help guitarists find more comfort and flow in their music, so they play more beautifully.
Click here for a sample formula.





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