Cannabis Humidity Packs for Long Term Storage: Buying Guide

Answer first: pick a two-way humidity pack rated 58% RH for long term storage

For cannabis you plan to store for six months or longer, a two-way humidity pack set to 58% relative humidity (RH) is the safest choice. This level prevents mold growth while keeping flower from drying out. Use an airtight glass jar, keep it in a dark place at 60 to 70 degrees Fahrenheit, and match the pack size to the amount of flower. Replace the pack when it turns crunchy or its indicator dot changes color.

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What to look for in a humidity pack

• Two-way control: The pack must add or absorb moisture to hold a target RH. One-way packs only add moisture and can over-humidify.
• Target RH: 58% for long term storage. 62% works for short term or if you prefer slightly stickier flower.
• Pack size: An 8 gram pack handles up to 1 ounce of flower in a small jar. A 67 gram pack handles up to 1 pound in a larger container.
• Food-grade materials: Look for packs safe for direct contact with plant material.
• Indicator: Some packs show a color change when exhausted. This helps you know when to swap.

Parameter bands for long term storage

• Relative humidity: 58% to 62% RH. Stay at the lower end for storage beyond three months.
• Temperature: 60 to 70 degrees Fahrenheit. Avoid swings above 75 degrees.
• Container: Airtight glass with a rubber gasket. Plastic bags and tins leak air.
• Light: Total darkness. UV light degrades THC and terpenes.
• Headspace: Fill the jar 75 to 90 percent full. Too much air speeds oxidation.

Common pitfalls to avoid

• Using too small a pack: A tiny pack cannot regulate a large jar. Match size to volume.
• Mixing RH levels: Do not combine 58% and 62% packs in one jar. The result is unpredictable.
• Refrigeration or freezing: Cold storage causes condensation when the jar warms up. That moisture invites mold.
• Forgetting to burp during cure: Humidity packs are for storage, not for the first two weeks of curing. Burp jars daily during that phase.
• Reusing an exhausted pack: A crunchy pack or one with a faded indicator no longer controls humidity.

FAQ

Can I use humidity packs for long term storage of concentrates? No. Concentrates need different humidity control. These packs are for flower.

How to Keep Cannabis Fresh in a Jar: A Simple Storage Guide

How often should I replace the pack? Every two to four months for long term storage, or when the pack feels hard and dry.

best cannabis storage containers for freshness

Do humidity packs affect terpenes? Quality two-way packs do not strip terpenes. They help preserve them by preventing oxidation.

What if my jar has no hygrometer? Add a small digital hygrometer. It gives you a real reading so you can adjust.