These Japanese tins (made in Shizuoka), with airtight lids, are ideal to keep your tea fresh. Being re-usable, they also reduce significantly the environmental impact vs. using new tins in every matcha shipment.
When you receive a re-fill pack of matcha, we recommend:
Consume your previous batch completely and wipe the tin clean with tissue paper.
Open your new re-fill pack and add its contents (through a sifter) into your tin. While this is not critical for freshly milled matcha, you will certainly enjoy 'fluffy' powder within your tin.
Ensure that the plastic (airtight) lid is properly placed.