What Is RH, and Why Does It Matter for Your Cannabis Stash?

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Every cannabis enthusiast wants the same thing: good bud, every time. And while several factors influence cannabis quality – the strain, curing, UV exposure, etc. – maybe the most important is RH. 

In this article, learn what RH is, why it matters for your stash, and what you can do to control it. 

What Is RH? 

RH stands for “Relative Humidity,” a measure of the amount of moisture present in the air compared to the maximum amount of moisture the air can hold at a given temperature. It’s always expressed as a percentage – for example, 50% RH, 75% RH, etc. 

Sound too technical? In lay terms, RH indicates how moist or dry an environment is. The deserts of the American Southwest will have a remarkably low RH, whereas the Florida Everglades typically boast a very high RH. Moreover, other factors can influence the RH in a contained environment like a house: water boiling on the stove, the shower running, inefficient windows, dryer venting, etc. 

How Relative Humidity Affects Cannabis

Cannabis is an organic material like any other. And just like other herbs, vegetables and plants, it will wilt or spoil in unideal conditions. 

In fact, cannabis is even more finicky than most plants, since its volatile flavor compounds and active cannabinoids (i.e., why we like it!) are particularly sensitive to humidity fluctuations. Let’s briefly explore how low and high RH impact cannabis, respectively.

Low RH

In drier conditions, cannabis will lose a lot of its flavor and aromatic nuances. The terpenes responsible for giving bud its trademark taste/smell mainly reside on the trichomes – those wispy hairs covering the flower. When cannabis dries, these terpene-rich trichomes slough off, taking the flavor with them. Further, research indicates that cannabis stored in low RH conditions loses its potency at a faster rate. 

High RH

At high RHs, cannabis encounters different problems. Even if it’s slightly too moist, it becomes difficult to smoke, often leading to “canoeing” joints or short-lived embers. And if cannabis reaches a certain moisture level (above 65%, roughly), you get into the dreaded mold territory. At these humidity levels, cannabis can rot, spoil and harbor mold, rendering it unsmokable. 

How to Control RH for Peak Cannabis Enjoyment

Thankfully, controlling relative humidity isn’t as technical or science-y as the definition might lead you to believe. It’s really a matter of creating a consistent, closed environment.

First, find an airtight container like a pop-top mason jar, Mylar bag, or dedicated cannabis storage bag. To shield it from UV exposure and high temperatures, keep it somewhere cool and dark. 

Next, buy Boveda moisture control packs, either online or at a local cannabis store or tobacconist. These packs feature a proprietary saltwater solution that draws in moisture when the RH gets too high and emits moisture when the relative humidity dips too low. In doing so, they maintain the exact RH listed on the pack (they’re available in 58% and 62% RH options). 

To make a long story short, you shouldn’t suffer through dusty, tasteless or spoiled weed. By understanding the impacts of RH and dialing it in, you can enjoy better cannabis. 

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