How does tea become bitter between the moment it is packaged and the moment I drink it? Are there any chemical processes that take place when tea is stored or brewed that I can control to prevent making a cup of bitter tea?

If the causes of bitterness vary between different types of tea, I'd like to know that as well.

  • 1
    Is tea bitter? So is coffee or cocoa. I think some people find fresh parsley or cilantro chutney bitter. I am sure carrots and apples drained off all their sugar and then dried would be bitter too.
    – Cynthia
    Commented Oct 25, 2012 at 3:31
  • @BlessedGeek If brewed properly, no. If brewed improperly, then yes, it's bitter. I actually asked this question because I had written the answer in response to another question that was then edited to be about something else entirely...if you think the question needs to be clarified, please go ahead and edit it.
    – Laura
    Commented Oct 25, 2012 at 14:22
  • 1
    @Laura I suspect that (like me) you just don't like the bitter tannin taste of black tea. Maybe try different herbal teas. My personal favourite is green tea with jasmine. (Note an answer below that points out different brewing temperatures, it makes a real difference)
    – Niall
    Commented Sep 13, 2014 at 13:02
  • Vanilla extract cuts bitterness.
    – Chloe
    Commented May 15, 2020 at 23:44
  • Curing of tea leaves is the secondary fermentation process which is done to increase the drinking potential and remove the bitterness and harshness by adding aromas and flavour to the tea leaves. It is carried out by the activity of Bacillus megaterium, also known as the bacterium behind the production of coffee and cocoa.
    – user95867
    Commented Oct 6, 2021 at 5:55

8 Answers 8


Storing Tea

You tea should never become bitter due to your storage methods. The only thing that should happen to tea as a result of how you store it is general loss of flavor or loss of the complexity of flavor (in a green tea, you might lose any honey or fruit notes of a tea that has been improperly stored, but it'll still taste like green tea).

There are a couple of factors at play when storing tea. The first is light. Exposure to light will degrade the quality of tea, stripping it of both color and flavor. Light also sets off a chain of reactions that destroys the antioxidants found in tea. So, you should store your tea in a light-blocking container (like a typical metal tea tin).

The next factor is air. Tea needs to be stored in a place that does not have any strong-smelling other foods or chemicals because it absorbs other odors very easily. In addition, tea absorbs moisture from the air, so it needs to be stored in a dry place. Moisture can cause several different problems with your tea: it could start binding to the tannins and make your tea taste bitter when you eventually brew it, and excess moisture could provide breeding grounds for bacteria or fungus, which would make your tea unfit for brewing at all. So, store your tea in an airtight container that blocks moisture and any other nearby odors. Vacuum sealing is not necessary, unless you want to keep a batch of tea for a long time without using it at all.

I haven't found any evidence supports claims of oxidation affecting taste more than moisture or light. Different types of tea are created by oxidizing tea leaves (white teas are the least oxidized, black teas the most, and greens and oolongs are somewhere in between), so oxidation is not inherently bad for tea.

To sum it up: Protect your tea from the harmful effects of light, moisture, ambient odors, and air by storing it in an airtight container in a cool, dark place. If stored properly, most kinds of tea leaves should retain most of their flavor for about two years, though fresher is always better. (Some teas, like Japanese green teas, are traditionally only stored for about 3 months.)

Brewing Tea

In order to achieve the best taste, brew tea according to the processor's instructions (at least to start with - once you become more familiar with tea and what you like, you can adjust according to taste). The tea manufacturer's want their tea to taste good, and they are experts, so you can rely on them to provide decent instructions. I've never bought tea that didn't have instructions for brewing right on the package, but in case you find some that don't have instructions, here are some general guidelines. I've taken this from Upton Tea's Brief Guide to Tea, and it corresponds to my own experience with making tea and chatting with tea importers / shop owners, too.

Whole Leaf Teas

  • black teas: boiling (212°F / 100°C) water, steep for 3-4 minutes; if serving with milk or lemon, steep 4-5 minutes
  • green teas: slightly less than boiling (180°F / 82°C), steep 2-3 minutes
  • oolong teas: lighter oolongs use warm (180°F / 82°C) water, steep for 2-3 minutes
  • white teas: less than boiling (180°F / 82°C) water, steep for 2-3 minutes
  • herbal tisanes: boiling (212°F / 100°C) water, steep for 5-8 minutes

Fanning, Crushed Leaves, or Powder

  • This is what most pre-bagged teas are, and since they have been processed to be finer, they require a shorter brewing time. (Finer leaves means more surface area, so you get more tannins per second when brewing, compared to tea leaves in larger pieces.)
  • Use guidelines above, but brew for 1-1.5 minutes less than whole leaf teas

The bitter taste comes from tannins. There are two ways for tea to become unpleasantly bitter: steeping at too high a temperature, or steeping for too long. (It's also possible that if your water is heavily chlorinated or otherwise impure that it could be making your tea taste bad, but that's far less likely than improper brewing.) If you're making tea from loose tea leaves, using too many leaves could also make your tea bitter; a good rule of thumb is 1 teaspoon of tea per 8 oz of water, though this can vary depending on the type of tea you're making.

Generally speaking, the longer you brew tea, the more tannins will be released and the bitterer the tea will be. If you use the times above as a starting point, you shouldn't get any overly bitter tea, but remember: each batch of tea is unique, and each tea drinker's taste is different. Experiment until you find what you consider to be the perfect cup of tea.

Lastly, start with good quality tea. Some tea is poorly processed and the flavor is ruined before you've even opened the package. If you start with a high-quality tea, you're much more likely to get good results. :)

  • 2
    I recommend drinking cheap low quality tea once in a while, with slightly more than normal sugar and milk. If you're feeling adventurous add one or two slices of ginger. If you're really adventurous add cardamom, clove and cinnamon. It's what 90% of tea drinkers consider "tea"
    – slebetman
    Commented Feb 23, 2016 at 9:17
  • 1
    The cheap black Ceylon stuff with pre-added cardamom is a nice switch sometimes, as is the addition of a teaspoon of orange-mint. Commented Feb 23, 2016 at 19:24
  • You mention too high of a temperature can lead to bitterness. Are there any rules of thumb for what temperature to steep at?
    – Caleb
    Commented Jan 21, 2017 at 6:48

For the amateur, less efficient or less experienced tea brewer like myself (even though I've been drinking tea for 35+ years) if your tea is bitter look at the following:

  1. water is too hot; I'm finding it's best not to boil the water (finer details are listed under Laura's response). I think that's why sun tea is so good, water is never exceedingly hot.

  2. tea bags are left in hot kettle or cup too long; maintain the 2-3 minutes brewing time, more or less as desired. Sometimes I get lazy or think more of a good thing is good, and leave the bags in the pot, resulting in nose crinkling and/or eye popping bitterness, which is not cured by adding more ice cubes or thinning with water.

  3. too many tea bags used in the brewing; the package would have me use twice as many as I usually prefer. One tea bag usually works for 2 cups/pint for me.

  4. and as another person stated, do not squeeze the tea bags. I used to do this to extract every bit of goodness, then realized I was squeezing lots of bitter tannins into my cup.

  5. a bit off topic, another tip I just learned in recent years: tea in a pitcher in the fridge should be consumed within a couple days as I've been told it will go bad, and a milky appearance does appear at the bottom of the container. I haven't researched this, so maybe producing fermented tea is desired by some, not that I've ever heard of that, just that fermenting foods and beverages seems to be all the rage of late. However, I've been told old tea can be bad for one's health.

BTW, I use tea bags, not loose tea, simply because I think the quality is still there, I'm not a "tea snob," not that there's anything wrong with that, and I lead a demanding life and loose leaf would only add to the challenges. It is fun on occasion to take the extra time and steps to enjoy loose leaf tea, if I can get my tea strainer or infuser back from my kids and get the Play-doh out. :)


Don't squish your tea bags to speed up the process, you will get bitter tea every time.


I learnt this trick when I was browsing the internet, but you add a little baking soda to your tea to make it smoother and less bitter.


Storage isn't really a relevant factor when it comes to the bitterness of tea. Bad storage can result however in aroma loss. Here are my notes for a less bitter tea experience:

  • Water temperature: brew tea with less hot water, while compensating this with longer brewing times.
  • Leaf usage: use less leaves to reduce the amount of bitterness.
  • Type: some more oxidized teas such as Tieguanyin oolong are less bitter. This is because the fermentation process smoothens out the bitterness, making the tea more soft.
  • Aging: some teas such as pu erh and white tea are suitable for aging. Over time these teas become less bitter an develop more sweet flavours.

The main culprit for bitterness or astringency is over-brewing. If you want stronger hair-raising and hearty tea, use a little more tea, and not brewing longer, to get the extra boldness of you like that. Or go to an extra hearty tea such as Assam, Scottish Breakfast, or either Irish or English Breakfast, in order of strength of tea flavor. Of course every brand can be different. I particularly enjoy purely Assam or a strong single estate tea in the mornings. If you love tea, do try some single estate teas. Subtle to stronger flavor differences in each and well worth the price and effort. Not super expensive but not Lipton tea-factory floor sweepings price either. I like Vahdam and Ghograjan estate teas.

Glengetti is a Welsh tea that is marvelous if you want strong tea. My first accidental stumbling on a Welsh tea and I loved it! It is a CTC loose tea, meaning it is cut, torn and rolled into little balls. Looks like a coarse instant tea but far from it. The only thing with it is using it in a very fine infuser or as I do, with Tea Sac I bleached filter paper empty bags to fill with your favorite tea and use to brew. Otherwise you will get a lot of “fallout” in bottom of pot or mug.


Don't brew it so long. I use a French press, toss in the loose tea, add near boiling water, stir, wait three minutes, and push the press down, isolating the tea from the liquid. Works Pretty well as long as I don't let the stuff sit half an hour or more. I expect this answer is heresy, but don't care because I get consistently tasty tea out of it, every morning.


Tea Quality

To avoid bitter tea, buy higher-quality tea. Bitterness comes from tea leaves being broken, often because they are harvested by machine. Hand-harvested tea is more expensive, obviously, but probably won't have that tannic taste. Here is a good website with better information: https://sevencups.com/learn-about-tea/how-to-judge-tea/

Add lemon to tea to reduce tannins, which can chelate iron from your food.

  • All tea is at least somewhat bitter, so bitterness cannot be just from leaves being broken by clumsy machines. Commented Jan 22, 2017 at 17:54
  • Matcha is tea powder, literally tea leaves ground into powder. They can't be broken more than that, but some matcha is good, and some is bitter. It doesn't have to do with broken tea leaves.
    – Chloe
    Commented May 15, 2020 at 23:42
  • And matcha is a more expensive tea. Exactly my point. Why has my answer has been downgraded? Really, there are too many factors to answer with one point. I merely stated one that had not been mentioned.
    – motorbaby
    Commented May 23, 2020 at 0:57

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