Cannabis Humidity Pack 62 vs 58: Which RH to Buy

Quick pick

Pick 62% for sealed jars you open once a week and keep for a month or longer. Pick 58% for flower you vape or roll within a week, or for a batch that arrived too wet and needs to dry down.

cannabis humidity pack 62 vs 58

What the number means

RH stands for relative humidity. A 62% pack holds air in a sealed container at about 62% RH. A 58% pack holds it at about 58%. Both are two-way packs. They release water vapor when the jar is dry and absorb it when the jar is wet.

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The window most cultivators cite for cured flower is 55% to 62% RH. Below 55%, trichomes turn brittle and terpenes leave with the moisture. Above 65%, water activity rises. Mold and powdery mildew need that moisture.

Cannabis Curing Humidity Packs: The Ultimate Guide

Boveda rates its packs to hold within 1 point of the label number. Integra Boost lists 55%, 62%, and 69% packs and puts a humidity indicator card in each box. There is no 58% Integra Boost pack.

62% packs

62% sits at the top of the target range.

• Slows moisture loss in dry rooms and dry states.
• Keeps flower pliable for 2 to 6 months in a sealed glass jar.
• Works for flower you plan to press or extract later.
• Drawback: a 62% jar in 80 F air can drift past 65% RH.

58% packs

58% sits in the middle of the range, 4 points below 62%.

• Flower grinds loose and burns even in a joint.
• Vaporizers produce more visible vapor at lower heat settings.
• Less resin buildup on grinder teeth.
• Drawback: at 3 to 6 months, 58% flower can read dry and harsh.

Sizes

Pack size matters more than the 4-point gap. Use one pack per container, sized to the flower weight.

• 1 g to 4 g pack: small jar, up to 7 g flower.
• 8 g pack: 1 oz jar or bag.
• 67 g pack: 1 lb bin or larger jar.
• 320 g pack: 5 lb container.

Check the label on the pack you buy. Ratings differ by brand.

How to choose

1. Test the flower first with a hygrometer. A $10 to $20 digital hygrometer in the jar tells you the current RH.
2. Read 55% or below: use a 62% pack for 24 to 48 hours, then recheck.
3. Read 63% to 66%: use a 58% pack and burp the jar for 20 minutes each day.
4. Read 67% or higher: skip the pack. Lay the flower on a tray and dry it first. A pack cannot pull that much water fast enough.
5. Read 58% to 62%: either pack holds the line. Pick 62% for storage, 58% for smoking.

What we do not know

No public study compares 58% and 62% packs side by side on the same cultivar over 12 months. Terpene retention data comes from producer testing, not peer review. Results depend on jar seal, room temperature, and starting moisture.