62% vs 58% Humidity Packs: Which One Should You Use?
Two-way humidity packs are small pouches that add or absorb moisture to hold the air in a container near a set humidity. The number printed on the pack is the humidity it aims for. The question most people have is which number to pick.
This guide explains how the packs work, why 62% and 58% are the two numbers you'll see most for dried herb storage, how the other common percentages are used, and how to avoid the mistakes that make packs seem not to work.
Quick answer
- 62% is the most commonly used option for curing and storing dried herbs. It keeps material on the softer, more pliable side.
- 58% is a common choice for people who prefer slightly drier material or live in humid climates.
- Packs are for holding a humidity level, not for drying wet material. Put them in once the material is close to target.
- Replace a pack when it turns stiff and crunchy. Store spares sealed in their original packaging.
- Use a hygrometer in the jar to confirm the pack is doing what you expect.
Equipment guide only. Growing, processing and storing cannabis is legal in some places and not in others, so follow the laws where you live. Nothing on this page is medical advice.
How two-way humidity packs work
A two-way pack contains a saturated salt solution in a pouch that lets water vapor pass through but not liquid. A saturated salt solution naturally settles at a particular relative humidity in a sealed space. If the air in the jar is drier than that level, the pack releases moisture. If the air is more humid, it absorbs moisture. That's the "two-way" part.
The key thing to understand is capacity. A pack can only absorb or release so much water before it is used up. That's why packs work well for holding material that is already near the right humidity and work poorly for fixing material that is far off, especially material that is still wet.
62% vs 58%: the practical difference
Four percentage points sounds small, but you can usually feel it in the material. Here's how the two compare in the way people commonly use them:
| 62% packs | 58% packs | |
|---|---|---|
| Feel | Softer, more pliable | Slightly drier and firmer |
| Common use | Curing and long-term storage; the most widely used option | Storage for people who prefer drier material |
| Climate fit | Fine in most homes | Often chosen in humid climates |
| Main concern | Too-moist material in a warm space; check for mustiness | Material can feel a bit dry for some preferences |
For most people, 62% is the right default. Choose 58% if you prefer drier material, if your storage area runs warm and humid, or if you've had issues with material feeling too moist at 62%.
Other percentages you'll see
Humidity packs come in many levels for different uses. You'll see these in searches and it helps to know what they're for:
55%
Offered by some brands for drier storage; on the low end for dried herbs.
58% / 62%
The two levels most used for dried herb curing and storage.
65% / 69% / 72%
Mostly sold for cigar and humidor storage, not dried herbs.
32%
Sold by some brands as a calibration kit for checking hygrometers, not for storage.
Higher-number packs are designed for different products. Using them for dried herbs pushes humidity higher than most people want.
How to use humidity packs during the cure
- Finish drying first. The material should pass the snap test on small stems before it goes in a jar.
- Jar it and wait. Put a hygrometer in the jar, seal it, and let it sit for several hours. This shows where the humidity naturally settles.
- Adjust before adding a pack. If the reading climbs well above your target, open the jar or take the material out to dry more. A pack can't fix wet material.
- Add the pack once you're close. When the jar settles near your target, drop the pack in to help hold it there.
- Keep checking. Glance at the hygrometer regularly in the first weeks. Many people still open jars briefly to let air exchange early in the cure.
Putting a pack into a jar of under-dried material and expecting it to pull the moisture out. The pack will soak up what it can, swell, and stop working, while the material stays too humid. Dry first, then use the pack to hold.
How many packs per jar?
Pack makers publish sizing guidance based on how much material each pack size is meant to handle. The common approach is to match the pack size to the jar and amount of material. Smaller packs are sold for pint and quart jars and larger ones for bigger containers.
Check the guidance on the packaging rather than guessing, and when in doubt, start with what the manufacturer recommends for your jar size. One correctly sized pack per jar is typical.
How long packs last and when to replace them
A pack is spent when it's used up its moisture or reached its absorption limit. The common signs:
- The pack feels hard, stiff or crunchy instead of soft and flexible: it has dried out and should be replaced
- The jar hygrometer drifts away from the pack's number and stays there
- The pack looks swollen after absorbing a lot of moisture (it was asked to do too much)
How long a pack lasts depends on how dry or humid your environment is and how often you open the jar. Store unused packs in their original sealed wrapping until you need them.
Humidity packs vs other options
Packs aren't the only way to manage jar humidity. Some growers use none at all and rely on careful drying, sealed jars and occasional opening. Others use rehydrating discs made of terracotta or similar material, which only add moisture and don't absorb it, so they're less forgiving. Two-way packs are popular because they work in both directions with little effort.
Whatever you use, a small hygrometer in the jar is the only way to know what's actually happening.
Common humidity pack mistakes
When people say humidity packs "don't work", it's almost always one of these:
| Mistake | What happens | Better approach |
|---|---|---|
| Adding packs to under-dried material | Pack swells, jar stays humid | Finish drying and let the jar settle first |
| Using a pack that's too small for the jar | Humidity drifts, pack is used up quickly | Match pack size to the maker's guidance for your jar |
| Trusting an unchecked hygrometer | You "fix" a problem that isn't there | Check the hygrometer with a salt test or calibration kit |
| Leaving spare packs unwrapped | They dry out or absorb moisture before use | Keep spares sealed in their original packaging |
| Using cigar-level packs | Humidity ends up higher than intended | Use packs sold for herb storage, usually 58% or 62% |
| Jars that don't seal well | Packs wear out fast fighting room air | Check lids and gaskets; replace worn ones |
A good rule: if the jar hygrometer and the pack disagree for days, look at the seal and the hygrometer before blaming the pack. Packs are simple; most problems come from the jar around them or from the material going in too wet.
It's also worth remembering that a pack is a buffer, not a thermostat. It smooths out small swings caused by opening the jar or by small changes in room conditions, but it won't override a poor seal, a warm storage spot, or material that was never fully dried. Get the drying, the jar and the storage location right, and the pack only has to do a small job, which is exactly what it's designed for.
Frequently asked questions
Is 62% or 58% better for curing?
62% is the most commonly used option and a good default. 58% suits people who prefer drier material or who store in humid conditions.
Can I put a humidity pack in with wet material?
No. Packs are made to hold humidity near a set point, not to dry wet material. Finish drying first, then add a pack once the jar settles near your target.
How do I know when a humidity pack is used up?
A spent pack usually feels stiff or crunchy instead of soft. If an in-jar hygrometer drifts away from the pack's number and stays there, replace it.
Can I use 69% or 72% cigar packs for herbs?
Those levels are designed for cigars and are higher than what is commonly used for dried herbs. Stick with packs sold for herb storage, usually 58% or 62%.
Do I still need to open jars if I use a humidity pack?
Many growers still open jars briefly in the early weeks of a cure to exchange air. A pack holds humidity but doesn't replace checking on the material.
Bottom line
Start with 62% unless you have a reason to go drier, then let a jar hygrometer confirm what's happening. Use 58% if you like firmer material or store somewhere humid. Above all, dry first and use the pack to hold the result, not to rescue it.
Follow the laws where you live, and check the pack manufacturer's guidance on sizing and storage.