How to store matcha after opening

Why does matcha lose quality after opening?

Matcha is a very fine powder made from whole tea leaves. Its surface area is huge. Oxygen, heat, light and moisture therefore act faster than on loose-leaf tea.

What suffers most is the chlorophyll, which gives the green colour, and the aroma compounds. The matcha turns duller in colour and flatter in taste.

A Japanese storage study shows how much temperature matters. Sealed matcha kept good quality for 24 weeks at 4°C. At 25°C it was only moderate after 24 weeks, and at 37°C it was clearly worse after just 3 to 4 weeks.

A Korean study from 2020 found the same pattern: the warmer and longer the storage, the less bright and green the powder. These results apply to sealed packs. With an open pack, every opening lets in fresh oxygen.

Why matcha is so sensitive as a powder is also explained in How is matcha made?

How long does matcha last after opening?

Every one of our packs carries a best-before date, one year from sealing. After opening, matcha tastes best within about 3 months if you store it as described below.

A simple calculation helps: one serving is 2g. A 60g pouch makes 30 servings, a 30g tin makes 15. To finish 60g within 3 months, you need about 2 to 3 servings a week.

Where is the best place to store opened matcha?

• Airtight: Close the pack right after each use. Our 60g pouch is resealable. If another pack doesn't reseal well, move the matcha into a tightly closing tin.
• Dark: Light breaks down chlorophyll. An opaque tin is better than a glass jar on an open shelf.
• Cool: A cupboard away from the stove, oven, coffee machine and window.
• Away from strong smells: Tea powder picks up odours. Keep it away from spices and coffee.
• Dry: Always use a dry spoon. Even a little moisture makes matcha clump.

Moisture is often underestimated. In a Korean study, green tea powder was stored for three months at different temperatures and humidity levels. At high humidity, catechins and vitamin C dropped markedly. Stored cool and dry, the powder stayed most stable.

Should matcha go in the fridge?

If you won't finish the pack within 3 months: yes. In our experience, opened matcha stays fresh for around 10 months in the fridge, as long as it is well sealed.

Two rules matter here:

1. Pack the matcha twice, for example the closed pack inside an airtight tin. That way it won't take on fridge smells.
2. Let the closed pack reach room temperature before you open it. Otherwise moisture from the warm room air condenses on the cold powder, like on a cold bottle in summer.

A practical routine: fill a small amount for the next one or two weeks into a tin for the cupboard. The rest stays in the fridge and only gets opened now and then.

Why not the freezer?

For unopened packs, cold is not a problem. In the Japanese study, sealed matcha also kept good quality for 24 weeks at minus 70°C.

For an open pack that you take out regularly, we still advise against the freezer. The temperature jump when you take it out is even bigger, and so is the risk of condensation. For everyday use, the fridge is the better choice.

How can you tell matcha has gone stale?

• Colour: Fresh matcha is bright green. Stale matcha turns dull and drifts towards olive or yellowish. The cause is chlorophyll breaking down into pheophytin, an olive-brown pigment.
• Smell: Fresh matcha smells green and slightly sweet. Stale matcha smells flat or takes on the smell of whatever was stored nearby.
• Taste: It tastes less of umami and more bitter.
• Texture: Firm clumps that don't crush easily point to moisture.

For a colour check, smear a little matcha onto white paper with your finger. In daylight you can easily see whether the green is vivid or turning olive. More quality markers are in How to spot good matcha.

Can you still use old matcha?

In Switzerland, the Federal Food Safety and Veterinary Office (FSVO, in German BLV) treats the best-before date as a quality date, not a use-by date. If a food still looks, smells and tastes normal after it, it can still be eaten.

Matcha that has lost colour and aroma doesn't have to go in the bin. It often still works well for baking or smoothies. If it smells musty or has got damp, throw it away.

If your matcha tastes bitter, age is not always the reason. The most common causes are in Why does my matcha taste bitter?

Which pack size fits?

Matcha is freshest when the pack size matches how much you drink. At fewer than 2 to 3 servings a week, a smaller pack is often the better choice, or you keep part of it in the fridge.

Our 30g tin makes 15 servings. At 2 servings a week, it is finished in just over 7 weeks.