Boveda Humidity Packs for Weed: What the Test Actually Showed

Last updated: August 2026

Quick answer: HWGrow’s three-jar test showed that a Boveda 62 pack can move sealed-container humidity toward its labeled range. It also showed the limit that matters most: every pack has a finite amount of moisture it can absorb or release. Once that working capacity is exhausted, the pack cannot keep correcting the container. Use humidity packs after drying and curing are complete and the flower’s humidity is already stable—not to stabilize wet flower or replace the cure.

Watch the complete Boveda 62 experiment

This first-party HWGrow video is the main source for the measurements below. It is a practical home experiment, not a laboratory validation of every pack size, container or starting moisture level.

Want the experiment in a focused player with the same captions and chapter controls? Open the Boveda humidity-pack video watch page. The article below keeps the complete written results, limits and curing context.

What HWGrow actually tested

Three sealed mason jars were stabilized near 52%, 62% and 72% RH. A Boveda 62 pack was added to each jar, the lids were sealed, and the hygrometer readings were recorded from one hour through two weeks.

The readings moved toward roughly 60–62% RH and remained close after two weeks. That supports the basic two-way-control claim in this setup. It does not prove that a small pack can safely remove the much larger and uneven moisture load inside under-dried flower.

Why a humidity pack does not replace curing

Curing is a controlled post-dry process in which moisture inside the flower redistributes and the sealed-container reading is monitored over time. A humidity pack can exchange only a finite amount of water. If the flower enters the jar too wet, the load can overwhelm the pack before the center of the buds is safe. If the flower is extremely dry, a small pack can also reach its limit while trying to restore moisture.

Think of the pack as a small shock absorber, not an automatic transmission. It can smooth normal drift around a stable target; it cannot make an unfinished dry or cure disappear.

Water activity and equilibrium relative humidity are related but are not identical to one instant reading from a cheap household sensor. The NIST legal-metrology summary describes the commonly used 0.55–0.65 water-activity range for cannabis flower. Primary postharvest research also shows that drying and curing conditions affect moisture movement and microbial levels; see the industrial-hemp drying and curing study.

When to add a Boveda pack

1. Finish drying first. Follow the complete cannabis drying guide. Do not seal obviously wet flower with a pack and hope for a rescue.
2. Run a no-pack jar test. Put a representative sample and a calibrated mini hygrometer in a clean airtight jar. Watch how quickly the reading rises before loading the entire batch.
3. Cure and stabilize. Use the complete cannabis curing guide until the container repeatedly settles in the intended range without the pack doing the heavy lifting.
4. Add the correctly sized pack for maintenance. Boveda’s own sizing guidance says a Size 8 is intended for up to one ounce of flower. Larger loads need the corresponding capacity; see the manufacturer’s sizing guide.
5. Keep monitoring. A pack does not sterilize flower, repair mold or guarantee that a leaky container is airtight. Replace an exhausted pack and investigate any unexpected RH climb, odor or visible growth.

58% or 62%?

Both numbers describe the pack’s intended equilibrium target, not a promise that every jar will land on the exact label. The manufacturer positions 62% for a softer or stickier feel and 58% for a slightly drier feel. Your container seal, temperature, sensor accuracy, flower mass, starting water activity and pack size all affect what you observe.

For most home growers, sizing and timing matter more than arguing over four percentage points. Use the pack only after the batch is stable, then choose the texture you prefer while staying inside a safe storage workflow.

What this experiment can—and cannot—prove

• It can show direction: the three jar readings moved toward the pack’s labeled range.
• It can show a practical limit: a small pack cannot exchange unlimited moisture.
• It cannot establish universal capacity: one pack size, three jars and household hygrometers do not cover every product size or storage load.
• It cannot replace inspection: flower condition, temperature, odor and visible contamination still matter.

Recommended storage tools

Boveda 62% Size 8 packsA maintenance option for already-stable flower in small airtight containers. Match pack capacity to flower weight and replace it when exhausted.
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Mini jar hygrometersUse one in each representative container and compare sensors before trusting a one- or two-point difference.
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Affiliate disclosure: HWGrow may earn a commission from qualifying purchases at no additional cost to you. Equivalent correctly sized packs, airtight containers and calibrated sensors can be substituted.

Frequently asked questions

Can a Boveda pack cure wet cannabis?

No. It has limited moisture capacity and should not be used to make under-dried flower safe. Dry and cure first.

When should I put a humidity pack in the jar?

Add it after the sealed-container humidity has stabilized near the intended storage range without the pack correcting a large moisture problem.

Why did the test settle near 60–61% instead of exactly 62%?

Household hygrometer tolerance, temperature, container seal and the pack’s working condition can all create small differences. Treat the label as a target range, not a laboratory guarantee.

Can a humidity pack prevent mold?

No. It is not a sterilizer and cannot repair contaminated or under-dried flower. Safe drying, clean handling, inspection and stable storage come first.

Want help with the complete harvest workflow? The Grow With Me Masterclass connects harvest, drying, curing and storage in one guided process without reproducing protected lessons here. If your jar readings do not match the examples, ask HWGrow and include container size, flower weight, starting RH, temperature, pack size and sensor model.