# Curing jar

> An airtight container, usually wide-mouth glass, used to cure and store dried cannabis; ideally filled about three-quarters and kept dark and cool.

- Canonical: https://genetixbay.com/knowledge/glossary/curing-jar.html
- Also written: cure jar, curing jars, mason jar, glass jar, jarring, jarred
- Glossary category: Harvest, drying and curing · Evidence: Grower practice
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

A curing jar is the sealed container in which dried buds cure. Glass is the standard: it is inert, gas-tight with a good lid, holds no odour and lets you see the buds. Wide-mouth jars are easiest to load and inspect. Other options include food-grade stainless or ceramic containers with airtight seals; thin plastic bags and porous containers lose aroma.

## In practice

How to use them:
- **Fill to about three-quarters**, loosely, so air can circulate and you can roll the buds when [burping](https://genetixbay.com/knowledge/glossary/burping.md).
- **Add a small calibrated hygrometer**, and read it only once the jar has equilibrated (several hours to overnight).
- **Label** cultivar, harvest date and jarring date, and in trials the wet and [dry weights](https://genetixbay.com/knowledge/glossary/dry-weight.md).
- **Store dark and cool**, about 15-21 °C (60-70 °F). Clear glass in light degrades [cannabinoids](https://genetixbay.com/knowledge/glossary/cannabinoid.md); keep jars in a cupboard or use amber or opaque glass.

For [long-term storage](https://genetixbay.com/knowledge/glossary/long-term-storage.md), once the cure is done, fill jars more fully to cut headspace and oxygen.

House position: no [humidity packs](https://genetixbay.com/knowledge/glossary/humidity-pack.md). If a jar needs moisture, add a fresh bud.

## Don't confuse with

- **Humidity pack**: a sachet sold for jars; GenetixBay doesn't recommend them.
- **Turkey bag**: a plastic oven bag used for bulk storage.
- **Vacuum container**: removes air but can crush buds.

## Related terms

[Curing](https://genetixbay.com/knowledge/glossary/curing.md), [Burping](https://genetixbay.com/knowledge/glossary/burping.md), [Equilibrium relative humidity](https://genetixbay.com/knowledge/glossary/equilibrium-relative-humidity.md), [Long-term storage](https://genetixbay.com/knowledge/glossary/long-term-storage.md)

## Read more

- [Curing and burping: jars, humidity and how long](https://genetixbay.com/knowledge/harvest-cure/curing-burping.md)
- [Long-term storage: keeping cured flower potent and aromatic](https://genetixbay.com/knowledge/harvest-cure/long-term-storage.md)

## Sources

1. Fairbairn JW, Liebmann JA, Rowan MG. 1976. The stability of cannabis and its preparations on storage. Journal of Pharmacy and Pharmacology 28(1):1-7. https://doi.org/10.1111/j.2042-7158.1976.tb04014.x
2. ASTM D8197. Standard Specification for Maintaining Acceptable Water Activity (aw) Range (0.55 to 0.65) for Dry Cannabis Flower. ASTM International. https://store.astm.org/d8197-22.html