Mold needs moisture. Keep cannabis at 55-65% relative humidity. Store in airtight glass. Keep temperature 60-70°F. Keep dark.

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Why Mold Grows on Cannabis

Mold spores are everywhere. They grow when water activity is high. For cannabis, that means relative humidity above 65%. Temperature above 77°F speeds growth. Light breaks down THC and can raise moisture.

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Ideal Storage Conditions

  • Relative humidity: 55-65%.
  • Temperature: 60-70°F.
  • Light: none.
  • Container: airtight glass.
  • Moisture content: 10-12%.

Containers and Tools

Use glass mason jars with airtight lids. Add a 62% relative humidity pack. Use a hygrometer. Keep jars in a dark cabinet. Do not use plastic bags. Plastic bags let air in and out.

how long does cannabis stay fresh in a jar

What to Avoid

  • Heat above 77°F.
  • Humidity above 65%.
  • Light.
  • Plastic bags.
  • Fridge or freezer. Moisture cycles.

Signs of Mold

White powdery spots. Gray or black fuzz. Musty smell. Mold can grow inside buds. Break open a bud to check. If mold is present, discard the whole jar.

How to Keep Weed Fresh Long Term: A Comprehensive Guide

Steps to Prevent Mold

  1. Dry cannabis to 10-12% moisture before storage.
  2. Put buds in a glass jar. Fill 3/4 full.
  3. Add a 62% humidity pack.
  4. Close lid tight.
  5. Store at 60-70°F in the dark.
  6. Open the jar for 5 minutes each week for the first month.
  7. Check humidity with a hygrometer.
  8. Remove any buds with mold.

Convenience drives cannabis storage choices. Pre-packaged jars and humidity packs save time. But they do not replace checking humidity and temperature. A $15 hygrometer prevents mold loss.