Can Tea Expire?
Updated: Oct 14
Shelf life of products is one of the more confusing topics in the tea world, mainly because there are so many different types of them. As much as not any bottle of wine is suitable for aging, so is tea. We must understand the principles by which the shelf life of each type of tea is determined and our role in maintaining their validity, before and after we have purchased them.
From a chemical point of view it is common to think that tea is invulnerable to spoil, on the other hand, thousand years of experience have dictates strict principles in preserving Chinese tea and identifying expired tea, even if the packaging indicates a date from the future. In fact, from the day western countries decided to adopt the dried camellia sinensis leaves (the tea plant) as a raw material into tea of their own, the original principles began to be obscured. Long shippings, extreme weather conditions, packaging that serves branding other than the material, loose export-import procedures, and of course innovative forms of mixing and serving, including tea bags, capsules and various blends - all created the situation where most of the tea available these days - is in fact, expired and isn't suitable for drinking, at least in Chinese standards.
It's true that "spoiled" is perhaps an extreme definition for dry natural leaves that hardly attracts parasites. It also unlikely that its consumption will cause extreme side effects, but it is clear that spoiled tea has lost many of its qualities and flavors, but mostly the benefits and value it used to have. Truth is, an expired tea does not justifies the price tag labeled on it.
Shelf life of tea can be determined by three criteria: the type of tea, packaging, and storage-shipping conditions.
Types of Tea
Different types of tea differ first of all in their production process, which defines their general framework of validity and when it is appropriate and recommended to consume them. While the shelf life of some types of tea is an integral part of the same production process, for others the biological clock is ticking, so most types of tea can be roughly divided into two groups: tea that is suitable for aging, and tea that doesn't.
Proper Tea Packaging
Perhaps the most important issue of all that many tend to neglect. Proper packaging that matches the type of tea and the shipping conditions it is about to undergo, maintains the validity of the tea according to the manufacturer's instructions. On the other hand, generic packages and reusable bags full of oxygen, are the number one cause of spoiling tea. A rule of thumb - the larger the amount of air in the package, the shorter the shelf life of the tea.
No less important than packing the tea is to take care of its storage, both during transport and in the store or at home. Slight changes in the weather or storage conditions of tea can cause an acute and irreversible damage.
Shelf Life of Tea by Type
Below is a guide that reviews the shelf life of the different types of tea and how we can help them prolong life. We will separate common packaging forms today and ultimate ones, and keep in mind that shelf life may also be varied between different subtypes of tea, so we will use an average time frame for each type of packaging. It is recommended to refresh the memory in an article on the differences between the different types of tea.
Green tea is the freshest and most sensitive of all teas, which should be stored inside the freezer in order to survive the summer, the main season of the year in which the Chinese consume it. Japan has different and more advanced finishing methods for green tea which defer from china in term of packaging and shelf life.
Packing: Sealed aluminum or plastic bag, recommended in a vacuum provided the shape of the leaves is not damaged
Storage conditions: Freezer (-20°C)
Shelf life: Up to 3 months loose in room temperature / 12-18 months in freezer
Divided into two categories of light wulong and dark wulong (also written Oolong), each has different instructions. In Taiwan the division isn't as clear since the tea leaves tends to be less sensitive and delicate than the original wulong from Fujian, and often undergone baking, so storage instructions may vary.
Packing: Thin aluminum bag / sealed plastic, vacuumed
Storage conditions: Freezer (-20°C)
Shelf life: 3-6 months in room temperature / 2 years or more vacuumed in the freezer
Packing: Sealed and thick aluminum bag
Storage conditions: Shaded and dry place
Shelf life: 6-12 months loose in generic reusable bag / 3 years or more in suitable packaging and proper storage conditions
White Tea & Pu'er Tea
White tea and Pu'er tea, which is divided into two categories of Sheng Pu'er (Raw Pu'erh) and Shu Pu'er (Ripe Pu'erh), share similar guidelines in terms of packaging & storage, simply because both are meant for slow natural fermentation by aging. Wrong packaging or storage conditions can do harm and irreversible damage, for example, if the tea dries completely it will cease to ferment and won't be improved. In order to prevent it, storage should stay away of strong odor such as perfumes, food and far away from detergents and other chemicals. Very important to keep the air stable as possible between 15-25°C all-year, and about 70% humidity. These types of tea are usually compressed into the form of "tea cake", "brick" or "dragon balls", what allows the tea to ferment slowly and safely. Under the right conditions also loose leaves will age, only faster, into a different tea profile result.
Packing: Airy paper / thin aluminum wrap
Storage conditions: A shady and odor-free place, 15-25°C, 70% humidity
Shelf life: Unlimited until fully fermented
Red Tea (Chinese Black Tea)
Red tea, or Black tea, is usually completely dried and the most difficult tea to get spoiled, what perhaps paved its way out of China towards destinations across the world, mostly to Europe.
Storage conditions: Shaded place
Shelf life: 3 years or more
dark wulong leaves from Wuyi Shan, packed in a large reusable paper bag that contains air (left) next to a single aluminum package for single use (right) to maintain the leaves fresh and as a whole.
How to Identify An Expired Tea
Plasticine (Play doh) Smell - the most common phenomenon in sensitive products that have undergone long journeys in the sea in various general packaging. The nostalgic smell from kindergarten days is one of the marks of spoiled tea that wasn't treated right.
Tea that has lost its taste and aroma - the easiest way to test is to brew a portion of leaves in gong fu cha (traditional Chinese method), in small batches of up to 200 ml at a time. If the same dose of tea fails to provide a rich and aromatic drink after 4-5 infusions (2-3 infusions for green tea) a sign that the tea is start to losing it.
What to look for when buying tea
Make sure you tea is packed right - packed well means sealed, packed right means with a suitable package for that particular type.
Look for the year of harvest (if it isn't there) - When aged tea has been aging well, its value will raise every year, while the harvest year will probably be presented proudly, but remember that only certain type of tea are suitable for aging. Most teas won't be effective and tasty anymore after sitting in storage for few years, waiting for costumers to order them. If the tea isn't suitable for aging and the year isn't shown - look for the tiny words or ask you supplier when it as harvested and packed.
Do not rely on expiry date mark ("best before") - In the world of food trade, must define as the manufacturer the person in charge of packaging the products and not necessarily the person who produces them, or in this case - grow the tea. The same "manufacturer" is also the one who imprints the date of manufacture and expiration on the packaging. In practice, this is a factor that allows for an absurd situation in which tea products are sold while they are actually expired, even though they still listed as valid.
Adventurous delivery - Big No No in the tea business. No matter the cost and quantity of your purchased tea, you do not want your package to go on a long adventure between different hands and random warehouses. That includes any shipping by boat, cheap & long postal services between multiple countries, and basically any shipping method take more than a month. Safe and fast delivery from door to door, even if expensive, will be kind to the precious tea leaves you've just purchased.