Quick Answer
Green tea that has been left to sit for several hours after brewing may lose some of its flavor and health benefits. However, it is generally safe to drink as long as it has been stored properly. The best practice is to brew a fresh cup of green tea and drink it while it’s hot or shortly after brewing. Leftover tea should be refrigerated and consumed within 24 hours.
What Happens to Green Tea Over Time
Green tea is made by steeping tea leaves in hot water. This allows the beneficial compounds in the tea leaves, such as polyphenols and catechins, to infuse into the water. Green tea contains several heat-sensitive compounds that provide its unique grassy flavor and potential health benefits.
When green tea sits out at room temperature for too long after brewing, several changes can occur:
- The tea oxidizes and loses its fresh flavor. Green tea has a relatively short shelf life.
- Some of the catechins that provide health benefits can degrade.
- Bacteria can start to grow, especially if sweeteners or milk have been added.
Overall, chemical changes to the compounds in green tea will alter its taste, aroma, and nutritional quality. The rate of these changes depends on factors like the temperature and how long the tea has been sitting out.
Short-Term Storage
It’s fine to drink green tea that has been left out at room temperature for up to 6 hours after brewing. Here are some general guidelines for short-term storage:
- Brew tea and let it cool slightly. Very hot tea will continue to steep and develop more bitterness if left to sit.
- Store tea in a sealed container to retain aroma and flavor. An airtight thermos works well.
- Finish drinking within 6 hours for best quality.
- The tea may gradually lose its warmth and become less palatable over time.
Long-Term Storage
For longer storage, it’s important to refrigerate leftover green tea or freeze it in ice cube trays. This better preserves the flavor and active compounds:
- Refrigerated green tea keeps for 1-2 days. Store it in a covered pitcher or jar.
- Frozen green tea cubes last 2-3 months. Keep them in airtight bags or containers.
- Label and date the tea so you remember when it was brewed.
- Avoid holding refrigerated tea for over 24 hours as quality declines.
To serve refrigerated tea, heat it up slowly on the stove or microwave in 30 second intervals. Thawed tea cubes can be used in beverages or simply drunk as is.
Avoid Room Temperature Storage
Leaving brewed green tea out at room temperature for over 6 hours is not recommended. The tea will oxidize faster, especially if it is exposed to sunlight or heat. Bacteria will start to multiply in the warm, moist conditions. If milk or sugar has been added, bacterial growth occurs more readily.
Here are the downsides of leaving tea out too long:
- Noticeable degradation in flavor, color, and aroma.
- Loss of nutrients, including catechins with antioxidant properties.
- Potential growth of harmful bacteria that can cause food poisoning.
- Increased bitter flavors from over-steeping.
For health safety, it is generally advised to discard any green tea that has been left unrefrigerated for over 24 hours after brewing. The compromised tea may cause stomach upset or other illness if consumed.
Does Green Tea Go Bad?
Green tea that is freshly brewed does not go bad per se, but it does degrade in quality over time. Young, high-quality tea leaves have an optimal shelf life of 12-18 months when stored properly in a cool, dark place. Refrigerating brewed green tea extends its shelf life up to a couple days.
So while unused green tea leaves stay fresh for over a year, brewed tea should ideally be consumed within a day. The nature of the drink means it oxidizes and loses flavor rapidly. However, properly stored tea that smells and tastes normal within 24 hours of brewing poses no safety risk.
Here are signs that green tea has gone bad and needs to be discarded:
- Foul, unpleasant odor
- Moldy patches or film on surface
- Strange colors or discoloration
- Curdled, chunky texture
As long as it does not exhibit these traits, green tea stored for under a day after brewing is perfectly safe to finish drinking.
Maintaining Freshness and Flavor
Follow these tips to keep homemade green tea tasting and smelling fresh for longer:
- Use high-quality green tea leaves within their prime shelf life. Check the expiry date.
- Store dry leaves in an airtight container away from light, heat, and moisture.
- Brew tea at correct temperatures to extract flavors properly.
- Do not over-boil tea, as this diminishes antioxidant content.
- Avoid over-steeping tea leaves more than 2-3 minutes.
- Pour tea into a clean thermos or jar with tight lid after brewing.
- Refrigerate leftover tea within 1-2 hours and use within 24 hours.
- Freeze excess tea in ice cube trays for longer storage.
Following proper brewing methods and storage helps retain the flavor, freshness, and health benefits of green tea.
Health Benefits Over Time
The beneficial antioxidants and other active compounds in green tea can start to degrade within a few hours of steeping. However, plenty of health benefits remain if drinking tea stored properly the same day it’s made.
Short-Term: 0-6 Hours
Green tea left out up to 6 hours after brewing retains much of its original nutrient content:
- Most catechins are still present to provide antioxidant activity.
- Polyphenols remain largely intact to combat inflammation.
- Compounds like L-theanine still offer calm, focused energy.
Long-Term: 24 Hours
Even after 24 hours refrigerated, green tea offers:
- A moderate amount of antioxidants from catechins.
- Some anti-inflammatory polyphenols.
- Small amounts of energizing caffeine.
Research shows properly stored, day-old green tea still contains valuable health-protective compounds. However, nutritional content declines with time. Drinking tea shortly after brewing provides the biggest benefits.
Safety Tips
Enjoying green tea that’s been left out for a few hours usually causes no issues. But take these precautions for maximum safety:
- Do not drink tea that smells or looks odd or is over 36 hours old.
- Avoid sweetened tea at room temperature, as sugar promotes bacterial growth.
- Discard tea that has been at room temperature over 6 hours.
- Store tea in the refrigerator and discard after 24 hours.
- Keep hot brewed tea over 140°F until drinking if possible.
- Do not reheat tea more than once.
Being mindful of proper brewing, storage, and reheating habits will help avoid contamination or illness from drinking old tea. Use good judgment when evaluating leftover tea’s freshness and quality before consuming.
Frequently Asked Questions
Is it bad to drink old brewed green tea?
It’s generally fine to drink green tea brewed within the past 24 hours if stored correctly in the refrigerator. Discard tea that is over 36 hours old or has been left out at room temperature over 6 hours. The tea will degrade in taste, aroma, and nutritional value over time.
Can you reheat brewed green tea?
Yes, it’s safe to gently reheat refrigerated green tea once. Bring it just to a simmer and avoid boiling to prevent further bitterness. Do not reheat tea more than once, as this can increase the risk of bacterial growth.
Does putting green tea in the fridge make it last longer?
Yes, refrigeration helps extend the shelf life of brewed green tea. Fridge temperatures slow down the growth of bacteria and oxidation rates. Covered tea in the fridge stays fresh about 24-48 hours.
Should you microwave brewed tea?
Microwaving is not an ideal reheating method. The uneven heating can create hot spots that damage delicate compounds in tea. However, it’s fine in a pinch. Heat refrigerated tea in 30 second bursts and stir between each to prevent overheating.
Is it OK to drink tea on an empty stomach?
Drinking green tea on an empty stomach is generally fine and may even enhance nutrient absorption. But too much tea before eating anything may cause minor stomach upset or nausea in some. Consider eating a small snack first if you experience discomfort.
The Bottom Line
Drinking green tea within 6 hours of brewing is perfectly safe and provides excellent flavor and health benefits. For best quality, freshly prepared tea is ideal. Leftover chilled tea stored properly retains some benefits up to 24 hours but loses freshness over time. Discard tea left out over 6 hours at room temperature or that smells or appears abnormal. Following proper methods to make, store, reheat, and consume green tea helps retain maximum nutrition and enjoyment.
