The main environmental conditions affecting the deterioration and aging of tea are temperature, moisture, oxygen, light and the interaction between them.
temperature
The higher the temperature is, the easier the appearance and color of tea will turn brown. Low temperature refrigeration (freezing) can effectively slow down the browning and aging of tea.
water content
When the moisture content in tea exceeds 5%, it will accelerate the deterioration of tea quality, promote the oxidation of residual enzymes in tea and deteriorate the color of tea.
oxygen
The oxidation of various substances that cause the deterioration of tea is related to the existence of oxygen.
light
Light irradiation will produce adverse effects on tea. Light can accelerate the progress of various chemical reactions in tea, and chlorophyll is easy to fade after light irradiation.
It can be seen from the above:
Reduce the storage ambient temperature.
Keep the proper moisture content of tea.
Block the contact between tea and oxygen.
Preventing direct light can slow down the deterioration of tea.
The storage method of tea is generally that the tea purchased by families is mostly canned or bulk tea. Since it is not soaked at one time after being bought back, it will encounter the problem of tea storage. The following suggestions are made for several kinds of tea storage commonly used by families. The methods are as follows:
Storage method of plastic bag and aluminum foil bag
It's best to choose the plastic bag with seal and used for food. The one with thicker material and high density is better. Do not use the plastic bag with taste or reproduction. The air in the tea bag should be squeezed out as much as possible. If the second plastic bag can be used to cover it reversely, it is better. The tea in a transparent plastic bag should not be exposed to the sun. The principle of bagging tea with aluminum foil is similar to that of plastic bag. In addition, the tea bought back is packed in bags, sealed and placed in the refrigerator, and then brewed in batches, so as to reduce the chance of contact with the air after the tea is opened and delay the occurrence of quality deterioration.
Metal tank storage method
Iron cans, stainless steel cans or tin cans with dense texture can be selected. If it is a newly bought jar or a jar that has previously stored other items with flavor, first put a little tea powder in the jar, cover it, shake it up, down, left and right, gently wipe the wall of the jar, and then dump it to remove the odor. There are stainless steel tea cans with two-layer lids on the market, which are simple and practical. It is better if they can be matched with clean and tasteless plastic bags, then put them into the cans, cover them with lids, and seal the cover with adhesive tape. The metal cans containing tea should be placed in a cool place, not in places with direct sunlight, peculiar smell, humidity and heat source. In this way, the iron cans are not easy to rust and can also slow down the aging and deterioration of tea. In addition, the tin can material is dense, which has a good effect on moisture-proof, anti-oxidation, light blocking and anti odor.
Low temperature storage method
Keep the tea storage environment below 5 ° C, that is, use cold storage or freezer to store tea. Pay attention to the following when using this method:
If the storage period is less than six months, the refrigeration temperature is the most economical and effective to maintain 0 ~ 5 ° C; If the storage period is more than half a year, it is better to freeze (- 10 to - 18 ° C).
It is best to store tea in a special refrigerated (frozen) warehouse. If it must be refrigerated (frozen) with other foods, the tea should be properly packaged and completely sealed to avoid absorbing peculiar smell.
The air circulation in the cold storage (freezer) is good to achieve the cooling effect.
When a large amount of tea is purchased at one time, small bags (cans) should be sub packed first, and put into the cold storage (freezing) warehouse. Take out the required brewing amount each time. It is not suitable to freeze and thaw the same bag of tea repeatedly.
When taking out tea from the refrigerated (frozen) warehouse, first let the tea temperature in the tea pot rise to close to the room temperature before taking out the tea. Otherwise, if the tea pot is suddenly opened, the tea is easy to condense water vapor and increase the water content, so as to accelerate the deterioration of the unfinished tea.