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3 things aroma can tell you about the quality of your cannabis

3 things aroma can tell you about the quality of your cannabis

By Allison Cohn

The olfactory evaluation of cannabis is as old as time. It’s a knee jerk reaction to take a big whiff of the flower you’ve just purchased. From the moment you bought your first dime bag, smelling the goods alerted you to its quality, potency and flavor.

Cannabis aroma is largely determined by its terpenes, or odor molecules. According to the International Cannabis and Hemp Standards (ICHS) glossary, the blend of terpenes in cannabis — or the terpene profile — is responsible for the cultivar’s unique aroma and contributes to its effects. As such, aroma is one of four key attributes evaluated as part of the qualitative data analysis during grading. Graders observe the smell of the flower to determine how well the terpenes have been preserved during the growing, drying, curing and storing process. A strong, pungent smell usually denotes flower without defects, and typically receives higher grades.

If you can smell the plant through the bag and from across the room, you know you’re in for a treat. The aroma of the flower, and therefore the preservation of its terpenes, can reveal a lot about how it was grown, cured and stored.


Cannabis plants tend to enjoy lower levels of nitrogen and higher levels of potassium and phosphorus during their growth period. Nutrients made from living sources such as kelp, guano, bone meal or worm castings can enhance the plant’s overall health, and therefore its aroma. Exposure to UV-B light may trigger a natural stress response in cannabis plants, causing more terpene containing trichomes to develop to protect the flowers from the powerful light rays, potentially positively affecting the flower’s aroma as a result. Growers sometimes utilize “living soil,” which contains active colonies of microorganisms, to provide additional nutrients for their plants to aid in trichome/terpene production.

And, of course, it’s crucial for cannabis plants to experience optimal temperature and humidity, since too much heat can burn the flower and negatively impact its smell. All of these variables during a plant’s life cycle can help or hinder its aroma, which is reflected in its final olfactory grade.


Since the smell of the flower is essentially a translation of the terpenes, the aroma of cannabis tells you a lot about how those terpenes were preserved. Properly cured flower should emit a powerful and dynamic aroma, ranging from berries to pine trees and everything in between. The aroma of high quality cannabis should be pungent, unique and have depth, which is best achieved by flawless curing.

Oxidation or extreme temperature fluctuation during curing can have a negative effect on a plant’s scent, causing the flower to become dried out and bland. Improper curing can also cause mold to grow if the plant is exposed to humidity or moisture. Common smell defects from improper curing include rotten, sour, ammonia, moldy and/or mildew scents.

You want your flower to be “stinky” in the sense that its scent is commanding, but not actually offensive. Weed that smells defective (or doesn’t smell at all) will receive a lower grade.


Storing cannabis properly is very important. If the plant is exposed to light, air or moisture, it may develop defects or become dried out, discolored and potentially lose its desired smells and flavors. Cannabis is also very sensitive to extreme temperatures and humidity. Exposure to moisture or humidity due to improper storage can cause the flower to grow mold, which will negatively impact its scent and flavor profile. If flower becomes mildewed from improper storage techniques, it will receive a lower grade.


High quality cannabis will have a depth to its aroma, ranging from what industry professionals refer to as top, middle and bottom “chords” of scent. Your top chords are the first impression aromas that disperse quickly, such as notes of citrus, floral or lavender. Middle chords are those scents that tend to linger for longer, like pine, pepper or earthy aromas. Bottom chords are the slowest to evaporate, like clove, ginger or jasmine. Cannabis that was grown and handled properly ought to omit a variety of commanding smells without having to be coaxed or broken apart to do so.

If the plant needs to be broken open or torn apart to release its smell, it will generally receive a lower score. Furthermore, if the flower smells dull, sour or mildewy, that’s a red flag that it’s defective or has been exposed to pests or growing conditions that caused mold to develop.

So whether your cannabis smells like sugary kid’s cereal or super heady incense, as long as that smell is strong and mighty, you’re probably looking at some good quality, healthy flower that was grown with care and provided with plenty of nutrients.


90-100 Aroma is very pungent, detectable from a short distance and before smell inspection is initiated.

80-89 Aroma is noticeable at close range before smell inspection is initiated. Flowers are pungent when broken open and smell test is performed.

70-79 Aroma is mild until flowers are broken open and smell test is performed.

60-69 Aroma is not present until after flowers are broken open and smell test is performed.

50-59 Aroma is dull or neutral but not indicative of defects.

>49 Lot smells sour, of mold, fungus or other defects

Read more in this series:
3 things color can tell you about the quality of your cannabis

3 things structure can tell you about the quality of your cannabis

3 things trichomes can tell you about the quality of your cannabis

Allison Cohn
Allison Cohn

Allison Cohn loves gold spray paint and nonsense. She also has a very difficult time sitting still and keeping quiet. She can often be found dancing like a fool when she isn’t hiding out in her mountain lair or gallivanting around the globe.