Drinking tea that has been left out overnight is generally not recommended. Tea that has been sitting at room temperature for an extended period of time can develop bacteria that may cause foodborne illnesses. However, the specific risks depend on the type of tea and how it was prepared.
Can you get sick from drinking old tea?
Yes, you can get sick from drinking tea that has been left out overnight or longer. When tea is left at room temperature for too long, it can grow bacteria that may cause food poisoning, stomach issues like nausea, vomiting, and diarrhea. This applies to all types of tea – black, green, white, oolong, etc.
Some of the common bacteria that can grow in old tea include:
- Bacillus cereus – causes vomiting and diarrhea
- Staphylococcus aureus – causes intoxication with vomiting and diarrhea
- Clostridium perfringens – causes diarrhea and abdominal cramps
- Salmonella – causes fever, diarrhea, abdominal cramps
These bacteria multiply rapidly at room temperature. The longer the brewed tea sits out, the greater the bacterial contamination. Drinking the contaminated tea can lead to foodborne illness, though symptoms may vary depending on the type of bacteria.
Does the type of tea matter?
Yes, the type of tea affects the risk of getting sick from drinking tea left out overnight. Here is a breakdown of how different types of tea compare:
- Black tea – Has lower risk than other teas due to higher antioxidant content, which inhibits bacterial growth. However, can still grow dangerous bacteria if left out too long.
- Green tea – Has higher risk due to lower antioxidant content than black tea. Green tea has a more neutral pH which allows more bacterial growth.
- Herbal teas – Varies by ingredient. Whole herbs and fruits in herbal teas tend to get moldy faster. Flavored or scented herbal teas have less risk.
- Chai tea – Has higher risk due to the milk and/or sweetener added. The dairy and sugar allow rapid bacterial growth.
- Iced tea – Has very high risk of contamination when left out. The cool temperature is ideal for rapid growth of many types of bacteria.
So in summary, black tea tends to be safer than green, herbal, chai, or iced tea when left out overnight. But this can vary based on preparation method and ingredients added.
Does the preparation method matter?
Yes, how the tea is prepared can impact the risk of bacterial contamination when left out overnight:
- Hot brewed tea – Lower risk than cold brewed. Hot water helps kill some bacteria during brewing. But others can still grow after brewing.
- Cold brewed tea – Higher risk than hot tea. No hot water to kill bacteria during brewing.
- Sun tea – Very high risk. Steeping tea at room temperature for hours is ideal for bacterial growth.
- Sweetened tea – Higher risk than unsweetened. The sugar feeds bacterial growth.
- Dairy added – Higher risk. Milk products can spoil and grow bacteria rapidly.
So hot brewing is safer than cold brewing in terms of minimizing bacteria when tea is left out. Avoiding sugar, milk, and steeping at room temperature also reduces risk.
How long until old tea becomes unsafe to drink?
There is no exact time frame for how long tea can sit out before becoming unsafe. It depends on the environment and storage conditions. However, here are some general guidelines:
- 2-4 hours – Best to refrigerate or discard
- Overnight (8 hours) – At high risk of bacterial growth. Do not drink.
- 24 hours – Very dangerous. Will likely cause illness if consumed.
- 1 week – Extremely toxic. Contains high levels of bacteria.
As a rule of thumb, tea should not be left at room temperature for more than a few hours. To be extra safe, it is best to discard any brewed tea that has been left out overnight and make a fresh batch.
What are the symptoms of drinking old tea?
The symptoms of drinking tea that has been sitting out depend on the type of bacteria growing in the tea. Common symptoms include:
- Nausea and vomiting
- Diarrhea and abdominal cramps
- Fever and chills
- Headache
- Fatigue and muscle aches
Symptoms can begin anywhere from 30 minutes to 48 hours after drinking contaminated tea. The illness usually lasts about 3-5 days but can potentially be life-threatening if the bacteria was highly toxic.
In severe cases, contaminated tea may cause symptoms similar to botulism, including blurred vision, difficulty swallowing, muscle weakness, and paralysis. Seek medical care immediately if very serious symptoms develop.
Who is at highest risk from old tea?
Some groups of people are at higher risk for getting sick from drinking tea left out overnight or longer:
- Young children
- Older adults
- Pregnant women
- People with weakened immune systems
- People with chronic illnesses
Healthy adults are still at risk but less likely to develop severe illness compared to higher risk populations. Infants should never be given tea that has been sitting out, as their immune systems are not able to fight the bacteria.
Does reheating old tea make it safe to drink?
No, reheating tea that has been left out overnight or longer does not make it safe to consume. Some types of dangerous bacteria produce toxins that are not destroyed by high heat. So while reheating may kill some bacteria, the tea can still contain toxins that will make you sick.
Additionally, some bacteria like Bacillus cereus form spores when heated. These spores allow the bacteria to survive high temperatures. The spores can germinate again in your gut after drinking reheated tea.
For optimal safety, it is best to properly discard any tea that has been left out too long and brew a fresh batch.
Can you tell if tea has gone bad by looking, smelling, or tasting?
It is difficult to detect contamination in tea that has been left out just by sight, smell, or taste. Tea that has gone bad may look, smell, and taste normal at first. Some signs that may indicate spoiled tea include:
- Cloudiness
- Mold on surface
- Slimy texture
- Strange colors
- Curdled milk in tea with dairy
- Sour or rotten smell
- Fizzing or bubbling
However, the absence of these signs does not guarantee the tea is safe. When in doubt, it is best to discard tea that has been sitting out for more than a couple hours and brew a fresh batch. Do not rely on appearance, aroma, or flavor alone.
Does the temperature matter?
Yes, the temperature at which tea is stored affects the rate of bacterial growth:
- Room temperature – Danger zone for bacterial growth. Ideal conditions for multiplying.
- Hot temperatures – Kills many bacteria, but some spore-forming bacteria survive.
- Refrigerator – Slows the growth of bacteria but does not kill them.
- Freezer – Stops bacterial growth. Freezing prevents tea from going bad.
Tea left out on the counter at room temperature has the highest risk of growing dangerous bacteria levels in just a few hours. Refrigerating tea can slow bacteria progression, but does not make tea last indefinitely.
Tips for drinking tea safely
To avoid getting sick from drinking contaminated tea, keep these food safety tips in mind:
- Don’t leave brewed tea out for more than 2-4 hours.
- Store any leftover tea in the refrigerator in a covered container.
- Throw away refrigerated tea after 24-48 hours.
- Never reheat tea that has been sitting out overnight.
- When reheating refrigerated tea, bring just to steaming hot.
- Do not leave tea sitting in direct sunlight for hours during brewing.
- Avoid adding milk or sugar to hot tea until ready to drink it.
Following proper brewing, storage, and handling guidelines will minimize the risk of bacterial growth in tea and prevent foodborne illness.
Conclusion
Drinking tea left out overnight or longer can lead to severe food poisoning. All types of tea can grow dangerous levels of bacteria like Bacillus cereus and Staphylococcus aureus when left at room temperature for too long. Higher risk teas include green tea, herbal teas, chai, and iced tea. Tea should not be left out more than 2-4 hours before refrigerating or discarding. Reheating does not make contaminated tea safe to drink. When in doubt, it is safest to brew a fresh batch of tea. Follow proper food safety guidelines when preparing, storing, and handling brewed tea.
