For immediate consumption or loose Pu'er Tea, storing it in a tin can is acceptable. You can use a tin can or a stainless steel can; initially, place a small amount of Pu'er tea dust inside the can and cover it to remove any peculiar smell from the can.

If it's a cake tea and you plan to store it long-term, it's best not to keep it in ironware for an extended period, as iron oxidizes easily in oxygen. However, if it's not going to be stored long-term, keeping it in a tin can is fine, because Pu'er tea does not need to be isolated from air. So how should Pu'er tea be stored long-term?
The best way to store Pu'er tea is with white cotton paper, as it has strong breathability and is suitable for long-term storage. Pu'er tea stored with white cotton paper will not come into large-scale contact with the air but also won't be completely isolated from it.
Pu'er tea can also be stored long-term in a purple clay jar, though it is relatively expensive and highly breathable. When you first buy a purple clay jar, you need to clean it inside and out with clear water, then soak it in water for a week (changing the water regularly), followed by drying it thoroughly in the sun, and finally allowing it to cool for two days. This is because purple clay jars are fired and have an Odor.

Earthenware jars can be used for long-term storage of Pu'er tea; they are inexpensive and have strong breathability. When choosing earthenware jars, make sure the inner walls are unglazed, as glaze on the inner walls inhibits breathability. The initial handling method for earthenware jars is the same as for purple clay jars.
A cardboard box is perhaps the most common container for storing Pu'er tea; it is cheap, has good breathability and moisture resistance, and is not easily broken.
Precautions for Storing Pu'er Tea
Precaution One: Temperature
The temperature has a significant impact on the storage of Pu'er tea. The temperature range for optimal transformation is generally between 20-30°C. Temperatures higher or lower than this range can affect the taste of the tea during its transformation process.
Precaution Two: Humidity
In addition to temperature, the humidity of the entire space needs to be maintained at around 65%-75% relative humidity.
During excessively dry weather, a humidifier can be used to increase the humidity of the air appropriately, or a damp towel can be used to wipe the floor, which serves both to remove dust and add humidity. During very humid and hot weather, the tea can absorb moisture from the air, leading to dampness and mold, so ventilation and dehumidification are also necessary.

Precaution Three: Ventilation
The transformation of Pu'er tea requires “breathing,” and oxygen and moisture are essential factors in this process. Therefore, Pu'er tea is best stored in a dry and well-ventilated area of your home. Oxygen-rich circulating air is beneficial for the proliferation of microorganisms in the tea and the transformation of its inherent substances. However, note that when we talk about ventilation, it doesn't mean placing it directly in the wind. Pu'er tea requires moderately circulating air!
Precaution Four: Cool Environment
Pu'er tea should be placed in a cool environment, away from direct sunlight yet sufficiently dry and ventilated. High temperatures can cause most teas to lose their activity, including Pu'er tea.
Precaution Five: Odorless Environment
Tea has adsorptive properties, so when storing Pu'er tea, attention must be paid to this. The place where it is stored must be clean and odor-free, and it should not be stored together with other teas to avoid flavor contamination.