There is no harm in leaving a tea bag in too long. But the over-steeping tea can make the tea taste a little more bitter and has an astringent effect in the mouth, leaving you feeling dry and puckery. Also, it may bring stains on your cup or teeth. By the way, it is suggested to steep the tea bags only once.
Steep time is one of the most important things to nail when it comes to brewing up a tasty, balanced cup of tea. Steep the tea for too long, and you'll end up with an unpleasantly strong, bitter cup. Steep the tea for too short a time, and you'll have a weak, flavorless cup of tea.
Generally not recommended. In the first step of brewing with hot water, the tea tannins and flavor compounds will be released in large amounts. After being refrigerated and cooled down, the tea flavor will be lost.
Patience plays a huge factor while using tea bags. You should leave the tea bag in the water for about two minutes so that there is ample time for it to infuse the tea flavor. Poking and prodding should be avoided, let the process happen naturally and slowly.
As with overindulgence of any kind, drinking too much tea can bring negative consequences. Even though tea is known to have health benefits, if you steep more than 10g worth of tea leaves a day, it can irritate the stomach and esophagus lining.
Generally speaking, you shouldn't use a teabag more than twice in 24 hours. After 24 hours have passed, the tea bag should be discarded. You can reuse tea bags more as long as they are kept in a place that is safe, but realistically a lot of people won't do that.
If you leave a 'traditional' tea bag for too long in water, the tea will turn bitter, as too much of certain chemicals (such as Catechins and other polyphenols) are released into the water.
Moist tea bags can be kept at room temperature for a day, but any longer and you will want to refrigerate them in a moist medium to prevent mold and bacteria growth. The smell test is your best measure of bacteria growth — if that bag smells funky, then toss it in the trash.
If you do accidentally leave your tea out, you can still enjoy it if it's been less than four hours. Just be sure to store it in the fridge as soon as possible. Brewed tea that has been left out for more than four hours should be thrown away. This is because bacteria can start to grow and cause food poisoning.
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.
Squeezing Out Tea Bags
Because of the high levels of tannic acid in tea, you're actually making the tea more bitter. It's not only weakening the taste, but it's also wearing the strength of the tea bags itself. By squeezing it, you run the risk of tearing the bag and releasing some of the tea leaves into your cup.
Foodborne pathogens can survive in brewed tea, but for tea brewed at an appropriate temperature–with water hot enough to kill pathogens–the issue of safety is primarily one of storage conditions and ensuring the tea dispenser has been cleaned and disinfected before use.
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.
Black tea has a high concentration of soluble oxalates, about 4.68 to 5.11mg/g of tea. These oxalates bind to the calcium, forming crystals that turn into kidney stones, and thus consumption of tea might potentially increase your risk of kidney stones.
While dunking your tea bag a few times, you're creating movement of water inside your cup. This flow makes it easier for molecules to move away from your bag. If you wouldn't move the bag, all those molecules need to move using diffusion only which does take longer to spread throughout the cup.
After you've poured yourself a cup, leave the bag in the pot. If you're served a cup already filled with hot water, put the bag in right away. After steeping about three to five minutes, remove the bag with your spoon and hold it over the cup so it can drain, then place the bag on your saucer.
A tea bag can be reused one or two times. After that, it's spent. Reusing green or white tea works better than darker blends. I usually reuse Orange Pekoe tea bags because I use two bags in one cup: I like strong milk tea in the mornings, with milk, and no sugar.
The sourness is the direct result of black tea's fermentation process. Black tea is fully fermented, and its fermentation is the key in the overall quality formation. Although there are many kinds of black tea products, the major tea-making steps are the same: withering, rolling, fermenting, and drying.
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.
Swirling and dunking a tea bag or infuser does move the tea leaves into contact with more of the fresh water in the vessel and aid in diffusion, but this is only nominally more effective than the diffusion that naturally occurs during the usual suggested three to five minutes of steeping time.
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.
Pay attention to the smell and taste
If the tea has mold, or if its aroma, appearance, or taste has changed, it's time to discard it. Those could be signs of bacterial contamination. Intentional Hospitality adds that freshly brewed iced tea should be kept in the fridge for no more than three days.
Clumping tea: If you shake your tea bag and the tea leaves inside clump together rather than sliding loosely inside the tea bag, then this is an indication that the tea inside may be contaminated with mold. Off smells: If your tea bags are infested with mold, they may have a musty or “off” smell to them.