How to Dry and Cure Your Harvest: The Complete Guide

You can grow a flawless plant for four months and undo the whole thing in four days. Drying and curing is the last stage, the least equipment-heavy, and by some distance the easiest to rush — and a harvest dried too fast smells of hay, harsh on the throat and flat in flavour, no matter how good it looked coming down. The good news is that it's mostly patience and two numbers: around 18–20°C and 55–60% humidity, held steady in the dark. Here's the whole process, from hanging the first branch to jars that are still improving a month later.

Why slow drying changes the result

A freshly cut plant is roughly three-quarters water. Drying removes most of it; curing removes the last stubborn bit slowly and evenly. The reason speed matters is that two different things need to happen, and only one of them is evaporation. Water leaves the plant quickly. The chlorophyll, sugars and starches left behind in the plant tissue break down much more slowly — and it's that breakdown that removes the green, grassy, "cut lawn" character.

Dry it in three days with a fan pointed at it and the water is gone before any of that chemistry has happened. You're left with something that is technically dry and permanently harsh. Take seven to fourteen days instead and the two processes finish together, which is where the smell and smoothness come from. There is no shortcut, no gadget that skips it, and no way to fix it afterwards — which is exactly why it deserves the same attention as your feed schedule.

Aroma is worth a word too. Terpenes — the volatile compounds behind the smell — start evaporating in earnest above about 21°C, and they carry on going the warmer it gets. A drying room at 25°C loses a noticeable amount of what you spent months building. Cool and slow protects it; warm and fast burns it off.

Setting up the drying room

You don't need a dedicated space — an emptied grow tent is ideal, and a spare cupboard or wardrobe works if you can control the air. What you're building is a dark, cool, gently moving, slightly dry box. Hang whole branches upside down from wire or a line, spaced so nothing touches anything else, or lay trimmed heads on a mesh drying rack if height is short.

Take the numbers seriously, because they interact. 18–20°C and 55–60% RH is the target, and the pair matters more than either alone: warm and dry strips moisture out in days, cool and damp invites mould. A cheap hygrometer sitting at head height in the room is the only way to know which way you're drifting — guessing by feel is how people discover on day four that they've been drying at 45%.

Air movement should be gentle and indirect. You want the room's air slowly turning over so damp air near the plants gets replaced, not a breeze across the material itself. Point a small oscillating fan at a wall or into the corner, never at the branches. And keep the room completely dark — light degrades the compounds you're trying to preserve, which is the same reason cured jars go in a cupboard rather than on a windowsill.

If the room won't sit in range on its own, control it rather than tolerating it. A British autumn will usually leave you fighting humidity upwards, not down — a house at 65–70% RH will stall a dry and start growing mould on day five. A dehumidifier on a humidistat is the reliable answer; for a single tent, a disposable hanging dehumidifier will pull a surprising amount out of a small sealed space for a few pounds. Our humidity control guide goes into holding a target RH properly.

Wet trim or dry trim?

There are two schools, and both produce excellent results — the choice is really about your room. Wet trimming means tidying everything up straight after cutting, while the leaves are still turgid and easy to grab. It's faster, far less fiddly, and the finished product looks sharper. It also dries noticeably quicker, because you've removed most of the water-holding leaf material — which is a problem if your room is already dry, and a blessing if it's damp.

Dry trimming means hanging whole branches with the leaves on and trimming once everything is dry. The leaves act as a buffer, slowing the whole process down and protecting what's inside them from drying out too fast. It's the better choice in a dry room, and most people find it produces a slightly better smell — but it's slower, messier work with brittle material, and you need the hanging space.

Whichever you choose, the tool matters more than people expect. Spring-loaded, non-stick trimming scissors will save your hands over a long session, and a resin-clogged blade tears rather than cuts. Keep a second pair and a little isopropyl to hand, and swap when the first pair gums up. If you're trimming a serious quantity, a bowl trimmer does the bulk work in minutes and you tidy by hand afterwards.

How to tell when it's actually dry

This is where the calendar lies to you. Seven to fourteen days is a guide, not a rule — a wet-trimmed small plant in a dry room can be ready on day six, and a fat whole-plant hang in a damp garage might take three weeks. Judge it by the plant, not the date.

The classic check is the snap test: take a branch and bend a stem. Small stems should snap cleanly with an audible crack; the thicker main stem should still bend rather than break. That combination means the outside is dry while the core still holds a little moisture — exactly the state you want going into jars, because the cure's job is to redistribute that last bit of water evenly through everything. If even the thick stems snap, you've overshot: it'll still cure, but it will never be quite as good.

A second check costs nothing. Put a handful in a sealed jar for a couple of hours and then open it. If the material has gone soft again and the jar smells damp, there's more water inside than you thought — back on the rack for another day. If it feels the same as when it went in, you're ready. For anyone doing this often, a moisture meter takes the argument out of it entirely.

Curing: the two weeks that do the work

Curing is simply storing dried material in a sealed container so the remaining moisture equalises, while the last of the chlorophyll and sugars break down. Airtight glass jars are the standard because glass doesn't breathe, doesn't hold smell and lets you see what's happening. Fill them about three-quarters full — enough air above for the atmosphere to matter, not so much that you're storing oxygen.

Then you burp them. For the first week, open each jar for about ten minutes once a day, which lets the humid air out and fresh air in. Week two, drop to every other day. After that, once a week is plenty. Two weeks is the minimum worth doing, four is where most people notice the difference, and six to eight weeks is where it stops improving much.

A two-way humidity pack takes nearly all the guesswork out. One 62% pack per jar will absorb moisture if the contents are too wet and release it if they're too dry, holding the jar steady while you cure. It won't rescue something soaking wet — a pack is a regulator, not a dehumidifier — but for the normal case it turns curing into something you barely have to think about. Small hygrometers that sit inside the jar are cheap and let you watch the RH settle: if it climbs back above about 65% after a burp, the contents needed longer on the rack.

What goes wrong, and whether it's fixable

A sharp ammonia smell when you open a jar is the one to act on immediately. It means anaerobic bacteria are working on material that went in too wet, and left alone it will ruin the jar. Tip everything out onto a rack, get air around it for a day, and jar it again once it passes the snap test properly. Caught early it's recoverable; left a week it isn't.

A hay or fresh-grass smell means the dry was too fast or too warm and the chlorophyll never had time to break down. There's no undo, but a long cure genuinely helps — leave those jars six to eight weeks, burping weekly, and most of it fades. Visible fuzzy mould is different and non-negotiable: discard the affected material, and don't try to save it by drying it out.

The gentlest failure is over-drying, where everything crumbles at a touch. Jar it with a 62% pack and give it a week — the pack will hand moisture back and it will soften considerably. It won't recover the aroma that went with the water, which is the real cost, but it becomes perfectly good again. And one thing not to worry about: a jar that smells slightly odd in the first two or three days is normal, and usually settles by the end of week one.

Quick answers

How long should drying take?

Seven to fourteen days at 18–20°C and 55–60% humidity. Wet-trimmed material in a dry room can be ready in about six days; whole plants hung with the leaves on in a damp space can take three weeks. Judge it with the snap test rather than the calendar — small stems snapping while the thick main stem still bends is the signal. Anything that finishes in under five days has dried too fast to smell right.

What temperature and humidity should a drying room be?

Around 18–20°C and 55–60% relative humidity, held steady, in complete darkness. The pair matters more than either number alone: warm and dry strips the moisture out in a few days and takes the aroma with it, while cool and damp risks mould. Above roughly 21°C you start losing terpenes noticeably. Use a hygrometer in the room rather than judging by feel.

Should I wet trim or dry trim?

Choose by your room's humidity. Below about 50% RH, dry trim — leaving the leaves on slows the dry down and protects what's inside. Above about 60%, wet trim, because that extra leaf material is what turns a slow dry into a mouldy one. Between 50 and 60% either works. Wet trimming is faster and neater; dry trimming is slower and messier but gives a gentler dry.

How often do I need to burp curing jars?

About ten minutes once a day for the first week, every other day in week two, then once a week after that. Burping lets humid air out and fresh air in, which is what stops moisture building up and turning anaerobic. If you use a 62% two-way humidity pack in each jar the schedule becomes far more forgiving, though it's still worth opening them in that first week.

Why does my jar smell like ammonia?

It went into the jar too wet, and bacteria are breaking it down without oxygen. Act the same day: tip it all out onto a drying rack, give it 24 hours of gentle air, and only jar it again once small stems snap cleanly. Caught in the first day or two it recovers completely. Left for a week it doesn't, and if you find fuzzy mould rather than just a smell, that material has to go.

Can I fix something I've over-dried?

Partly. Seal it in a jar with a 62% two-way humidity pack and leave it a week — the pack releases moisture and the contents will soften back to a normal feel. What you can't get back is the aroma that evaporated along with the water, so it will always be a little flatter than it should have been. Never try to rehydrate with fruit peel or damp paper; that's how you introduce mould.

Do I really need to cure, or is drying enough?

Drying makes it storable; curing makes it good. The cure is where the last of the chlorophyll and sugars break down, which is what removes the grassy edge and lets the smell come forward. Two weeks in jars is the minimum worth doing, four weeks is where most people notice a clear difference, and improvement largely stops somewhere around six to eight weeks. It costs nothing but patience and a few jars.