Relative Humidity (RH): How to control humidity to extend the life of your dried products.

We know that storing dried herbs/goods requires a durable stash jar. The jar’s rigid shape protects the integrity of your herbs. Add UV protection, and you’re almost ready to keep your products staying their freshest. 

Too many consumers assume a glass jar is enough. It’s an important step but they forget a missing essential component — managing humidity.

What is RH, and why is it important?

Relative Humidity (RH) measures water vapor or moisture relative to the air's temperature, a percentage that compares the current atmospheric moisture with its capacity. RH affects the aromas and flavors of your organic goods, which changes your product's effectiveness.

A humidity-controlled environment prevents additional damage to your herbs. Too much moisture increases the risk of contamination by growing mold or mildew. Lack of humidity will cause herbs to dry out completely. It becomes brittle and ineffective because of losing the product’s natural oils.

Determine your RH levels.

Not all dried goods are created equal. Before you buy anything, it’s essential to know the suitable RH level for your herbal goods. Different ingredients or materials have other storage requirements. 

To help you save some time and effort, check out the RH table we made below.



Afterward, determine the RH level of your room/house (the RH level of your stash container). You can do this with the following methods: 

1. Use a Digital Hygrometer. 

The most accurate way. Many digital thermometers have built-in hygrometers to give your RH readings. 

2. Hair Hygrometer Test. 

If you do not have a hygrometer, you can use a strand of hair and some household items to make one. You can learn how to conduct the hair hygrometer test here

3. Ice Cube Test. 

Place two or three ice cubes into your glass stash container.

Add water and then stir it. Wait three to four minutes, then observe the glass walls. The air is low if moisture does not form outside the glass. If water condenses on the outside of the glass, the relative humidity level is high.

Once you have both RH levels (environment and desired RH for your product). It will help you determine if you need to increase or decrease the RH level of your jar. 

Controlling Humidity Levels

Humidity Bags

Plastic bags may work for short-term transportation. But they are not enough for long-term preservation. Humidity bags solve that problem. You can use a humidity bag for optimal portability or long-term storage. Know they’re a minimalistic, lightweight, and less durable option than glass jars. For a great quality humidity bag, we recommend the BLOOM Humidity Bags. It’s reusable, has a built-in humidity regulator (55-62% RH), and is made of recycled, non-toxic materials. Need we say more?

You can buy the Bloom Bags here.

Humidity Packs

Humidity packs are small little pouches containing a saline solution.

Humidity-controlling packets are the most inexpensive and popular option. We can see why. The BLOOM 2-way humidity packets are ideal for those who already have a stash jar. The packets convert your container into a humidity-controlled atmosphere. One packet can last for up to 1 month. Bloom humidity packs respond to storage conditions by absorbing or releasing moisture. All to guarantee a 62% RH.

Get the Bloom Humidity Packs here.

Some points to consider:

  • Do not store anything in the freezer or refrigerator. The change in temperature under these conditions increases the chance of mold growth.
  • Do not store other items together with your herbs. Depending on the material, it may contain destructive oils that contaminate your herbs.
  • Avoid storing your products near heat. The heat can still overpower your humidifier and over-dry your dried goods.

A little effort with a significant impact.

There you go! Relative Humidity is a crucial element in keeping your products fresh for longer. After reading this article, you can see that it does not require a lot of money, time, or resources to prolong the quality and life of your herbs— you only need a little effort and knowledge. Humidity-controlling products are a small investment for your herbs and will save you money in the long run.