For example, Chiki Tea’s matcha is packaged at the source in specially-engineered airtight tin box packaging and flushed with nitrogen to eliminate oxygen oxidation and to keep the tea fresh until it is opened. In addition, a further barrier is affixed to the lid to absorb the oxygen after opening.   Gently open the tea metal tin canister over a sink as the matcha will “smoke” and leave a small residue floating in the air.   Once the matcha is opened, it’s time to start daily whisking because matcha does not age gracefully! Don’t be tempted to save it as long as you can because of the cost. The best flavors and aromas will be within the first three weeks if stored properly so that air is kept to an absolute minimum. Matcha should be kept in the fridge, optimally in the airtight canister, it has been packaged in and used within 3 weeks for the freshest taste, aroma, and color.   To use, take the matcha out of the fridge and wipe off any condensation. Have your tools out and ready, your preparation bowl and chasen heated, and then open the matcha metal tin canister, scoop out the desired amount, and quickly close the lid. Oxygen and moisture are the biggest factors in deteriorating all Japanese tea but especially matcha, due to the particle size.   Unopened matcha can be stored in the freezer for a year or longer but when it’s opened, promote it to the fridge and consume it quickly. It is possible to extend the freshness of the opened matcha by placing it in the freezer; however, because condensation is a matcha killer, the container needs to be wiped and left for a few minutes to stop the condensation buildup before opening. This is ideal if your 100g canister takes longer than a month to consume.