Best RH for Weed in Jars: 62% vs 58% Picks

Best RH for Weed in Jars

Two numbers cover most of it. Flower in a sealed glass jar holds at 62% relative humidity. Long storage and vaporizer flower run at 58%. The rest are short term fixes. The picks below come from two-way humidity packs, the product that sets RH inside a closed jar.

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The Pick: 62% RH

62% fits flower opened two or three times a week. At that level the pack adds moisture when the jar runs dry and pulls it back when the flower sits damp. Boveda 62% and Integra Boost 62% both do the job. Water activity lands near 0.60 aw, inside the 0.55 to 0.65 aw range in ASTM D8197. Trichomes stay intact. Buds stay pliable without feeling wet.

ideal humidity for curing cannabis

Second Pick: 58% RH

58% suits jars that sit closed for months and flower headed for a dry herb vaporizer. Lower RH gives mold less room. The cost shows up in terpenes. Each time the lid comes off, dry air enters. Flower at 58% loses aroma faster than flower at 62%.

cannabis storage humidity percentage

Options at a Glance

• Boveda 62%: sizes 4 g, 8 g, 67 g, 320 g. Use one 8 g pack per ounce of flower in a quart jar. Two-way. Salt and water inside a membrane.
• Integra Boost 62%: sizes 4 g, 8 g, 67 g. Same job, different membrane. Ships with a replacement indicator card.
• Boveda 58%: same sizes as the 62%. Pick for storage jars and vaporizer flower.
• 55% packs: for flower that must burn clean in a joint. Drier bud, harsher smoke.
• 69% packs: rehydration. Drop one in a jar of brittle flower for 24 to 48 hours, then move the flower to a 62% jar. Do not store at 69% long term.

Jar Setup

1. Use a mason jar with a rubber gasket lid. Fill to three quarters. Headspace air is what the pack conditions.
2. Match pack mass to flower mass. One 8 g pack covers up to 1 oz (28 g) in a quart jar.
3. Store at 60 to 70 degrees F in a dark cabinet. Heat drives terpene loss.
4. Check the pack each month. A stiff or crusty pack is spent. Replace it.
5. Add a small hygrometer if the jar gets opened often. Packs hold RH, but a bad lid seal shows up as a slow drop.

Common Mistakes

• Sealing damp flower. A pack cannot dry flower fast enough to stop mold. Dry to 62% first.
• Using one pack for a pound. Large jars need the 67 g or 320 g pack.
• Reusing a spent pack. Once the core turns solid, the pack is done.
• Storing in plastic. Plastic passes moisture and odor. Glass does not.