Green tea is a warm drink made from the steeped leaves of the aptly named tea plant. Unlike black tea or other forms of tea from the same plant source, green tea is the relatively fresh and unprocessed version of the leaf, meaning it is more likely to be susceptible to spoilage and loss of quality1.
While tea leaves in their dry and ground up form can last up to an entire year, once brewed, green tea will only last as long as five days in the refrigerator. This is, of course, assuming that the proper storage procedures and conditions have been met.
How Long Does Brewed Green Tea Last Out in the Open?
Once the green tea leaves have been brewed and steeped, it is best to either consume it immediately or use the storage methods mentioned later in this article, as brewed tea left exposed to the elements will only last up to eight hours.
The reasoning behind this is the growth of certain species of fungi that can tolerate the acidic properties of tea. Even if not immediately visible atop the surface of the tea, fungal spores may have already begun to develop, which produce harmful toxins to the human body.
How to Store Dry Green Tea Leaves
If instead you have not yet brewed the green tea leaves and simply have them in their dried form, storing them is far easier.
In order to store dry green tea leaves, all that is needed is an air-tight container and an area in your kitchen or pantry with low temperatures and no direct sunlight.
Simply place a single piece of tissue paper along the bottom of the air-tight container before emptying the tea leaves into it.
Ensure that the area the container is stored in is free of excess moisture or high temperatures, as these will accelerate the spoiling of your tea leaves. It is also prudent to ensure the tea leaves are not stored near any particularly strong-smelling items, as tea leaves will absorb these scents readily.
Can you Refrigerate Brewed Green Tea?
In short – yes, refrigerating brewed green tea is the ideal way to keep it fresh and in drinkable form. If refrigerated properly, green tea can last as long as five days, as previously mentioned.
Keep in mind that refrigerating green tea requires an opaque container with an air-tight cover.
In order to allow the brewed green tea to last as long as possible, allow the tea to cool to room temperature before placing it in your air-tight container.
Leave as little open air as possible between the container cover and the tea, as excess air will interact with the tea, weakening its flavor and reducing its antioxidant effects.
Can Brewed Green Tea be Frozen?
If instead choosing to forgo refrigerating your brewed green tea in favor of storing it in the freezer instead, it is vital to keep several things in mind.
Freezing your green tea, especially that of the Japanese variety2, will absolutely weaken its taste and reduce the beneficial health effects it may have on you. This is mostly unavoidable, as the physical effects of crystallizing can break down chemicals in the tea.
Additionally, the act of freezing will decrease the total moisture present in the tea, taking vital flavonoids with it.
How to Freeze Brewed Green Tea
In order to freeze your green tea, all that is required is an ice tray and cling wrap to insulate the tea from the air.
The best method to freeze green tea in advance is to brew it in a higher concentration than you would normally drink it at. Using less water at higher temperatures will allow the leaves to release more of their flavor and chemicals, producing a more concentrated tea.
Once sufficiently extracted, place the concentrated green tea into ice trays, taking care not to allow any tea to connect with another divot, as these will freeze into a single block.
After filling the ice tray, cover with plastic wrap and leave in the freezer for up to six months. Keep in mind that any additives in the tea such as sugar or preservatives may affect how it freezes.
To make the tea drinkable again, simply a small quantity of water and drop the concentrated ice cube into it.
Do these Procedures apply to other Teas?
Yes, in fact, these procedures apply even better to other forms of tea, so long as it also comes from the tea plant.
In order to produce black tea or similar teas, the leaves are withered under dry heat and oxidized in a processing room. These rigorous processes create a more durable leaf that presents a stronger taste, allowing it to suffer the damaging effects of long-term storage with less quality lost3.
Keep in mind that this is not exactly true for fruit teas, as the process to produce these and the chemical make-up that they possess is far more different than traditional tea plant leaves.
How to Know if Green Tea has Gone Bad
Determining whether or not green tea has begun to spoil is difficult owing to the less-than-obvious nature of the microorganisms that colonize brewed green tea.
Primarily, the best method to check for signs of spoilage is to smell the green tea. Any alcoholic or rancid odors emanating from the tea is a sure-fire sign that bacteria have begun to grow in your tea. Throw this tea out.
Apart from off-scents, the appearance of floating masses beneath or even atop the surface are most likely aggregate growths of mold, and as such the entire batch of tea is likely dangerous to consume. Should you notice this, discard the tea.
Keep in mind that tea leaves vary in color once brewed due to a multitude of factors. This is entirely normal – especially if frozen or refrigerated over a long period.
1. Unknown Author. (September 2016) “Green tea”. National Center for Complementary and Integrative Health, US National Institutes of Health.
2. Kei Nishida. (March 2018) “THE BEST WAY TO KEEP MATCHA & GREEN TEA IS TO FREEZE – TRUE OR FALSE?” japanesegreenteain.com
3. Li, Guang, Ling Chun Chin (ed.). (2007) “The Art of Tea” Wushing Book Publisher