What are the best containers to store loose tea?
Iron containers, paper containers or others？
Most teas need to be stored in an air tight and light tight container with the possible exception of puerh which is usually best stored in something breathable like a Yixing container. As far as non puereh teas go I use mostly metal tea tins that I have bought. You can also use glass if you keep it somewhere away from light as light can cause tea to degrade.
Tea should be stored dry and away from direct sunlight and bad odours. Most teas should be stored well sealed in a pouch or tin or other type of container. However, for pu erh tea it’s ok to allow it to ‘breath’. Additionall, for green tea and light oolong teas, you ideally want it to be stored frozen. Make sure it’s sealed carefully before you freeze them.