Matcha can have a gentle bitterness, but it should not taste aggressively harsh.
When it does, the most common causes are water that is too hot, too much powder, too little liquid, stale matcha or a matcha that is not suited to the way you are preparing it.
Your Water Is Too Hot
Boiling water is one of the fastest ways to make matcha taste bitter. Very hot water pulls out more of its sharp and astringent flavours while covering up the softer sweetness and umami.
Let freshly boiled water cool before whisking. A practical range is around 70°C to 80°C. Without a thermometer, leave the kettle open for a few minutes or pour the water into another cup before adding it to your matcha.
If your matcha suddenly tastes less bitter after lowering the temperature, the powder was probably not the problem.
You Are Using Too Much Matcha for the Amount of Liquid
More matcha does not always create a better drink. A large scoop in a small amount of water can taste concentrated, chalky and bitter, especially when you are drinking it without milk.
Before adding sweetener to fix a bitter cup, try adding a little more water or milk. The ratio may simply be too strong.
Read our guide on How Much Matcha Powder Should You Use explains how to adjust the amount for different drinks.
You Are Drinking a Stronger Matcha Straight
Some matcha is blended to stay noticeable in a latte. That stronger character can be useful with milk but may taste more robust, vegetal or bitter when prepared only with water.
For matcha tea, look for a powder described as mellow or suitable for usucha.
Your Matcha May Be Old or Poorly Stored
Matcha begins losing freshness after it is opened. Exposure to air, heat, light and moisture can dull its colour and turn its flavour flatter, stale, and more bitter.
Keep the package tightly sealed and store it somewhere cool and dark. Avoid leaving it beside the stove, near a sunny window or open on the counter. A dry spoon also helps prevent moisture from entering the package.
Learn how to How to Store Matcha Powder.
The Matcha Itself May Be Naturally More Bitter
Matcha flavour changes with cultivar, growing region, harvest timing and processing. Some powders are naturally softer and sweeter, while others have a more assertive profile.
Late harvest matcha and inexpensive powders often have stronger bitterness.
A mild bitterness can be part of matcha. What you are trying to avoid is a harsh flavour that overwhelms the fresh green notes, sweetness and umami.
Read What Does Matcha Taste Like? for a flavour reference.
Clumps Can Create Bitter Pockets
Clumps do not make the entire drink more bitter, but biting into a concentrated pocket of dry matcha can make it seem that way.
Sift the powder before adding water, then whisk until it is fully dispersed. This creates a smoother texture and a more even flavour from the first sip to the last.
Bitterness Is Usually Fixable
Start by lowering the water temperature and checking your matcha-to-liquid ratio. Those two changes solve many bitter cups.
If the flavour remains harsh after careful preparation, look at freshness, storage and whether the matcha is appropriate for water or milk.
