Open a jar of cannabis from certain producers and you may find, nestled amongst the flowers, a small square sachet. Its purpose is simple enough, to help regulate humidity and keep the flower in better condition for longer. For patients, it can be reassuring, after all, nobody wants medicine that is too dry or at risk of mould.
Humidity-control sachets work by maintaining relative humidity (RH) at a set equilibrium point, usually around 58–62%. Inside the sachet is a saturated solution of salts and water, encased in a permeable membrane. This creates a two-way system: when the surrounding environment is too dry, water vapour is released; when it is too humid, excess moisture is absorbed back in. The goal is to buffer against fluctuations that can drive biochemical changes in plant material, such as terpene volatilisation, oxidation, and cannabinoid degradation. By keeping RH stable, sachets help preserve aroma, texture, and perceived potency. In other industries, cigars, coffee beans, even wooden musical instruments—this approach makes perfect sense, as those products either benefit from, or cannot be harmed by, ongoing chemical stability once processed.
“The goal is to buffer against fluctuations that can drive biochemical changes in plant material”
In cannabis, they can play a role too, particularly in consumer markets where storage conditions vary widely. They can help revive dry flower, reduce brittleness, and keep the product usable. But in medical cannabis, the expectations and requirements are different. Medicines are produced under strict standards such as EU-GMP and the European Pharmacopoeia, which already set clear specifications for residual moisture content, typically around 8–12%. These limits are carefully designed to protect against mould while preserving the plant’s natural character.
From this perspective, sachets are more of a safety net than a necessity. When drying, curing, and packaging are done carefully in controlled environments, cannabis can remain stable within the required range without the need for anything extra in the jar. And it’s important to note: sachets don’t add anything to the flower itself. If cannabis hasn’t been properly dried or cured, a sachet won’t magically correct those shortcomings; it can only maintain what’s already there.
Some patients also feel that sachets, while functional, can subtly change the aroma or mute the natural terpene profile; not an outcome anyone intends.
“Cannabis can remain stable within the required range without the need for anything extra in the jar.”
At Dalgety, we’ve chosen to focus on the upstream process rather than downstream fixes. Our flowers are dried and cured slowly under tightly monitored conditions, allowing moisture to stabilise naturally and terpenes to settle without disruption. By the time our products are sealed, they already meet the pharmacopoeia standards for moisture and stability, and are tested to stay that way over their shelf life.
That isn’t to say sachets are “wrong” or that companies who use them aren’t meeting standards. Different producers take different approaches, and for some, sachets may be a practical solution. But for us, their absence reflects confidence in the process itself.
Ultimately, what matters most is not whether a jar contains a sachet, but whether the flower inside is safe, stable, and effective. Patients deserve consistency and transparency and that’s what guides our approach.
