Quick answer

Glass jars cure cannabis because glass holds humidity, blocks odor, and does not react with terpenes. Use a clean jar with a tight lid. Fill it to 75% of volume. Keep the flower at 58% to 62% relative humidity and 60°F to 70°F. Open the jar for 5 to 15 minutes each day during week one. The cure runs 2 to 8 weeks.

cannabis curing jars with boveda

Why glass beats plastic and metal

Glass is non-porous. It does not absorb terpenes and it does not hold a static charge. Plastic containers hold static that pulls trichomes off the flower. Plastic is also oxygen permeable, so flower dries out over weeks. Silicone is worse. Metal tins rust at the seams when humidity sits at 62%. Mason jars, bail-top jars with rubber gaskets, and amber apothecary jars all work. Amber or violet glass blocks light in the 400 to 500 nm range. That matters because UV light converts THC to CBN.

how long to cure cannabis in jars

Jar size and fill level

Fill a jar to about 75% of its volume. The other 25% is headspace for air and moisture to move. A 16 oz jar holds about 1 oz of dried flower. An 8 oz jar holds about 14 g. A 4 oz jar holds about 7 g. Use several small jars when the harvest comes from different plants or harvest dates. If you pack flower tight, mold risk goes up.

Cannabis Curing Jar Setup Guide

Humidity and temperature targets

Two-way humidity packs rated 58% or 62% hold the range in a sealed jar. Add one pack per 1 oz of flower. Replace the pack when it turns stiff or crunchy. A small hygrometer inside the jar gives a real number. Cheap analog hygrometers drift by 5% or more, so calibrate with a salt test first.

cannabis curing jar sizes

Burping schedule

Burping releases moisture and gases. Open the jar, wait 5 to 15 minutes, then close it. Keep jars out of direct light while they sit open.

  1. Days 1 to 7: open 2 or 3 times per day, 5 to 15 minutes each time.
  2. Days 8 to 14: open once per day, 5 minutes.
  3. Weeks 3 to 4: open every 2 or 3 days.
  4. Week 4 and after: open once per week to check smell, texture, and humidity.

Turn the jar so buds on the bottom move to the top, then close it. If buds stick together or the smell turns to hay and ammonia, leave the jar open longer. Ammonia points to anaerobic bacteria. Spread the flower on a rack for 12 to 24 hours, then start the cure again.

How long curing takes

Two weeks is the minimum for smokeable flower. Four to eight weeks gives the full terpene profile. Chlorophyll and sugars break down in that window. The hay smell fades and the strain smell comes forward. Past 6 months, terpenes oxidize and potency drops. Store long term at 58% RH in the dark, sealed.

Cleaning and lid choices

Wash jars with hot water and dish soap. Rinse. Let them air dry upside down for 24 hours. Any water left inside grows mold. Metal two-piece lids with a plastisol liner seal well and cost little. The liner wears out after 10 to 15 openings. Bail-top jars with rubber gaskets reseal many times, but the gasket collects plant material and needs replacement every year or two. Do not use a lid that smells of pickles or garlic. Rubber holds odors, not glass.

What not to do