In most cases, old tea will simply be less flavorful than it should be, and taste dull or stale. While old tea isn't usually dangerous to consume, it's definitely a less than ideal tea drinking experience. If your tea tastes like it's gone bad or if you spot visible mold or other signs of decomposition, steer clear.
The best way to know for sure if your tea has gone bad is by smelling it. If it smells like rotten eggs or mold, then it's definitely time to throw it out. Also, over time mold may begin to grow on the surface, this is another sign that your tea has gone off and needs to be thrown away.
As mentioned, tea bags do not expire. Neither does loose leaf tea. Dry tea leaves and bags are typically good for a whopping two years before quality starts rolling down a hill. All teas made from the camellia sinensis plant, whether green or black teas, will begin to lose their flavor over time [3].
Brewed tea will slowly lose its complexity of flavor if left at room temperature for more than a few hours. The tea will eventually sour if left for more that 12 hours. It varies a lot among tea types, some will be fine for at 24 hours.
One of the best ways to judge a tea, of course, is by the taste. Green tea should taste fresh, not stale, and should not be too astringent. Black tea should be full bodied and fresh. In general, good tea has a sweet aftertaste and should feel very slippery going down the throat.
In most cases, old tea will simply be less flavorful than it should be, and taste dull or stale. While old tea isn't usually dangerous to consume, it's definitely a less than ideal tea drinking experience. If your tea tastes like it's gone bad or if you spot visible mold or other signs of decomposition, steer clear.
This oxidation process may be stopped by either roasting or steaming the leaves before they are completely dried out. Through fermentation, the originally deep green leaves become reddish-brown color. The longer is the fermentation, the darker is the color.
When tea sits around for too long, a substance called TP (tea polyphenol) that it contains will start to oxidise, this darkens the tea. A great example would be green tea, its color will turn from bright green to yellow when put in a high heat environment.
If iced tea is brewed at inadequate tem- peratures or in an improperly cleaned urn, or if it is stored for too long, it may grow coliform bacteria, most frequently Klebsiella and En- terobacter, and less commonly E. coli.
You always have the choice to reheat the tea. However, doing so might steal many of its flavours, nutritional properties and aroma. If you have left your tea abandoned for more than four hours, it is downright not recommended to reheat the tea as it may harbour mould and bacterial growth.
The Compost Pile: One of the easiest uses for your unused, unwanted, and/or expired tea bags is to simply add the tea bags to your compost pile. Tea bags and brewed tea alike can aid the decomposition within your compost pile. You should definitely remember to put tea and tea bags in the compost, not the garbage.
Poor quality water
If you find yourself wondering why your tea tastes funny there's a good chance that it's down to the water. For the best, liveliest cup of tea you want freshly drawn water which is rich in the oxygen needed to draw out flavour.
In short, both tea leaves and tea bags retain good quality for about 6 to 12 months past the best-by date.
Tea bags can grow mold on either the tea bag or the tea itself. Mold is found in any environment that contains a high level of humidity. Mold can be prevented in tea bags by keeping them in an airtight container and keeping your tea in a low-humidity environment.
Tea really only gets rancid if it's near water. So if you haven't stored your tea well, humidity and moisture may get to it and break down the leaves, causing mold. In that case, you should obviously throw that tea out immediately.
Smell: Generally, the aging time of mildewed tea is relatively long, which carries strong dusty and musty odor. There's even smoke when the package is opened in some cases.
If you're worried that drinking expired tea after the best by date will make you instantly ill, don't worry - only in extreme cases will old tea make you sick. However, it's likely that any tea consumed beyond a recommended best by date will start to taste bad and bitter, a natural sign that your tea has gone bad.
The short answer is, don't store tea for more than 8 hours at room temperature. If you left your tea out at room temperature overnight or longer than 8 hours, it would be best to discard it. It's not worth the risk if tea is left out overnight.
“We found in green tea,” Professor Krehenwinkel, the lead author on the study, told The Scientist, “up to 400 species of insects in a single tea bag.” That's a lot of bugs in your teacup.
Tea bags will be fine for at least a year in the pantry, but even long after that, they're still safe to consume. They just might change colour or flavour. If your tea has an expiration date then it's just for best quality, not safety.
Protect tea from its enemies: Store tea in a cool, dark place away from light, heat and moisture. Light and heat can activate enzymes that will start to degrade your tea. And tea is shelf-stable because it's completely dry.
Drinking Too Much Tea May Cause Negative Side Effects
If you are drinking more than 9 cups a day, you might be overdoing it. Many types of tea contain caffeine which, when overused, can cause anxiety, unwanted stress, poor sleep, increased stomach issues, headaches, heartburn, and create caffeine dependency.
Oxidation is a process through which tea leaves are exposed to the air in order to dry and darken, contributing to the flavor, aroma, and strength of different teas. Just as other fruits and plants, like apples or avocados, brown when exposed to oxygen, tea leaves go through a similar process after they are harvested.
Kombucha tea has caused stomach upset, infections and allergic reactions in some people. Kombucha tea is often made (brewed) in homes under unclean conditions. This makes it likely that bad bacteria can grow. Also, when the tea is made with ceramic pots that have lead in them, lead poisoning happens.