How to Prevent Hay Smell When Drying Cannabis?


It is always a horrible nightmare for indoor cannabis growers that we have the “hay smell” at home after drying their marijuana buds. It is frustrating for everyone, especially since we cannot find the exact reason for the cause. So why do buds sometimes smell bad or “harsh” or like hay after they’ve been dried?

We’re going to cover this today and go through ways to make your cannabis smell great as soon as they are done drying. Curing buds in jars will make the smell stronger and smooth to smoke, but there is no point where they will smell “bad.”

3 efficient ways to prevent the “hay smell” when drying cannabis buds 

a) Air dries the cannabis buds in a cool place (best) – Cut off some branches and put their buds on drying racks. Make the room temperature between 60-70°F (15-20°C) while drying; gentle air circulation is also a must.

b) Cannabis bud dryer – Using a cannabis-specific dryer/dehydrator. Even though it is the dryer, especially for cannabis, you still have to get a proper temperature for your buds because they are easy to be over-dried.

c) Air drying the cannabis buds in a cardboard box or paper bag – If you do not have a cool place or a budding dryer the last option you have is to air-dry in a box or a paper bag. A paper/cardboard bag will create a good environment for bud drying; it is like a small drying room.

Hanging your buds upside-down in the box, ensure your buds are separated from each other, and let them dry with good air circulation. You can also leave the top open or cut some slits on the side of it to get better air circulation. Be aware that your buds will most likely start to get that hay smell when air-dried in a warm place so try to keep the environment as cool as possible (under 70 °F/20 °C).

Why do poor drying conditions make cannabis buds smell bad? 

The reason we think poor drying conditions cause a hay smell is the specific breed of microorganisms or bacteria that grow in those more humid conditions. This is just a theory—others may have a different idea—you are welcome to share your ideas with us through since this is just our theory. We did a few testers for drying buds to see what would happen and this is what we found.

In the first drying attempt, we hung buds in a closet with a fan. In only a day or two, all the buds were dried with no hay smell, but they looked crispy and bad. Also, they were harsh to smoke. We got poor results because the buds dried too quickly.

In our second attempt we put our buds into the same closet but this time without a fan. It took a long time to dry those buds—approximately 3 days—and the hay smell was stronger than before.

For the third test, we hung the entire plant upside down in the closet with no fan in it. It took about 7 days to dry all the buds thoroughly. Still hay smell was there and the buds in the middle of the plant grew mold—so try to avoid this method.

There are two factors we ignored that we decided to address for the final test: the temperature in the closet. We turned on the air conditioner and cooled the space to 62°F/17°C, and controlled humidity at about 50% RH. At this time, it took about 10 days to dry, and the buds had zero hints of hay smell. They looked better and smelled better than before, and the smoke was super smooth.

Why does my weed smell like hay

There could be a few reasons why your cannabis might smell like hay:

  1. Improper Curing – If the cannabis was not properly cured after harvesting, it can develop a hay-like aroma. Proper curing helps preserve terpenes (compounds that give cannabis its smell/flavor) and prevents a hay smell.
  2. Age – As cannabis ages, it loses its terpene profile over time. Older cannabis that has been improperly stored can take on a hay or grass-like scent as it dries out.
  3. Poor Storage – Storing cannabis improperly by exposing it to too much air, heat, light or humidity can cause it to degrade and lose its terpenes faster, resulting in a hay-like smell.
  4. Genetics – Some cannabis strains naturally have more hay/grass-like terpenes as part of their terpene profile when harvested properly. However, a predominant hay smell usually indicates a cultivation or storage issue.
  5. Contaminants – In some cases, a hay smell can indicate the presence of contaminants like mold or bacteria if the cannabis was mishandled.

What about dryness and over-drying? 

Some beginners are always confused about this: hay smell is caused by microorganisms, not over-drying or over-dry buds; dried-out buds are gross but the smell is not that hay smell. Over-drying and low-humidity drying is one problem and the hay smell is a different one. Over-drying and low humidity will make the buds crispy and look bad.

This is what we have learned about drying cannabis—we hope it helps you on your journey, too! If you have anything or any thoughts to add to this page, let us know, leave your comment below, we welcome different voices! For example, how do you dry the buds? What is your humidity level while drying? Also, pictures would be a plus if you could share them with us. We would love to help our growers to get the best weed themselves.

How to get rid of hay smell during drying?

  1. Proper Drying Environment:
  • Maintain temperatures between 60°F – 70°F and humidity levels between 45% – 55% in the drying area.
  • Ensure good air circulation with fans, but avoid directly blowing air on the drying buds.
  • Consider using a dehumidifier if humidity is too high.
  1. Drying Racks/Screens:
  • Use stackable drying racks or screens to allow for maximum air flow around the buds.
  • Don’t let buds lay on solid surfaces where moisture can get trapped.
  1. Frequent Bud Rotation:
  • Gently rotate and reposition the buds on the drying racks every 12-24 hours.
  • This prevents flat spots and allows for even drying.
  1. Darkness:
  • Keep the drying area dark to prevent degradation of terpenes from light exposure.
  1. Monitor Moisture Levels:
  • Use a hygrometer to track the relative humidity around the drying buds.
  • Remove buds when the smallest stems snap cleanly to prevent over-drying.
  1. Air Purification:
  • Use an air purifier with a HEPA filter to remove contaminants that could cause off-smells.
  • Consider using an ozone generator cautiously between drying cycles.

If you have any questions, please don’t hesitate to reach out to us!

And be sure to check out our other blog posts for useful tips on becoming a great grower!

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