Bud Moisture: When to Jar?
After harvest comes the moment most growers guess at: are the buds dry enough for the jar? A €10–20 pin meter turns that guess into a number. Here's how to mea…
The harvest is hanging, the dry is under way – and then comes the question most people end up guessing at: when do the buds go into the jar? Too early, and three days later there's mould in the jar and the harvest is gone. Too late, and the buds are brittle, the terpenes have evaporated and the smoke is harsh. The stem-snap test is a matter of experience, and experience is exactly what you don't have the first time round. There's a simpler answer: a number. 🌱
The whole thing in 75 seconds is also up as a video on TikTok – this is the part behind it.
What the thing is – and what it costs
It looks like a stun gun, but it's a moisture meter with two pins . You can get one from €10, and at €10 to €20 you're genuinely well equipped. The same meters also come with a 420 printed on them – then they cost €70. That's essentially the exact same device you get for €20, just with a different print. You don't need anything expensive.
The meter from the video is this one: moisture meter on Amazon (affiliate link to the German Amazon store – see the note at the end of this guide). It sits in the €10–20 class, exactly the one I'm talking about.
Strictly speaking these are wood moisture meters. Hence the most important step before you measure anything: set the meter to "Wood 1" – on meters that use letters instead of numbers, that's the first setting, mode A. And then leave it on that mode for good, otherwise today's numbers won't be comparable with next week's.
What it actually measures – and why the number still works
The meter measures electrical resistance between the two pins. Wet material conducts better, so it shows a higher number. The scale is calibrated for wood – and a bud is not wood. Different salts, different sugars, different density. So the number on the display is not a true water content in percent . Anyone telling you "at exactly 12 percent it's done" is selling you a wood scale as flower truth.
Why the meter is still worth its weight in gold: same device, same mode, same way of measuring – then the number is reproducible . You can see whether it's drier today than yesterday, whether the big bud is wetter than the small one, whether something is shifting inside the jar. A comparative value is all you need for drying. The numbers below apply to exactly this class of meter on "Wood 1". If you have a different device, calibrate it once with the cross-check at the end of this guide.
How to measure properly
1. Into the thickest bud, right to the core. A bud dries from the outside in; the core around the stem stays wet longest. The surface lies, the core doesn't. So don't just touch the pins on – push them in.
2. Measure several buds, not one. The wettest one counts. A single bud that's too moist is enough to mould an entire jar.
3. Always measure the same way. Same depth, same pressure, bud at room temperature. A cold piece straight out of a cool drying room reads differently from a warm one.
4. Use a test bud. The pins leave holes, so don't sacrifice your best one. The same bud can later be taken out of the jar as a sample, measured and put back.
The numbers I work with
- Above 15: keep drying. Nothing to discuss.
- Below 15: now you can slowly start thinking about putting the buds into jars. Many people jar at 15. Personally I wait until 14. One more point of patience costs you a day – one point too early can cost you the jar.
- In the jar: every now and then take a sample, pull a bud out and measure it. Between 11 and 12 is where I like it best. That's where it settles on its own in the jar if everything else is right.
- Below 10: now it's getting dry and brittle. A humidity pack in the jar softens that a little, but it's better not to get there in the first place.
One thing that startles a lot of people once the buds are jarred: in the first few days the number on the outside often climbs back up. That's not a fault – it's the core handing its moisture over to the dry outer layer, the so-called sweating. That's exactly why you measure to the core and not at the surface. If a bud reads above 15 again after a day in the jar, everything comes back out to dry a bit longer. Open the jars briefly every day in the first week; after that, less often is fine.
The precise cross-check: jar and hygrometer
If you want to know for sure, you don't need a more expensive meter – you need a small hygrometer for a few euros . I use the Xiaomi Mi Monitor 2 (affiliate link, German Amazon store): 43 millimetres small, fits in the jar, shows temperature and humidity – and my controller can read it over Bluetooth. Put it in the sealed jar, wait 24 hours, read it. The humidity that settles inside the jar is the equilibrium humidity of your buds – and that is practically the quantity labs measure as water activity. Their target window is 0.55 to 0.65, which means 55 to 65 percent in the jar . Above that it gets risky for mould, below it's too dry. 58 to 62 is the middle where buds stay stable for months. …
Bud Moisture: When to Jar?