Henna is perishable and must be stored properly to leave good color.
Henna Powder Storage
Unopened henna powder can be stored in any cool dry place for 3 years. For long term storage, put it in the freezer.
Once you open henna powder, expose as little henna as possible to the air and wrap it tightly for storing.
Henna Paste Storage
If using henna paste within a few days, storing the paste in the refrigerator is fine. Anything longer than a few days should be stored in the freezer to keep it fresh. It only takes about 15 minutes to thaw a henna cone. Do not leave henna out at room temperature any longer than necessary.
Henna can be unpredictable. I have used henna that was left in the fridge for over 3 weeks and got great color, however I’ve used henna that was in the fridge for only 4 days and got terrible color. Take the extra steps to protect henna paste for the very best color.
Old henna is great for practicing henna designs, but never use old henna on paying clients or when you want a good henna stain.