Clumping in Matcha: A Red Flag?

You’ve opened a new tin of matcha and notice some clumps in your tin. You’re disappointed. Well, don’t be just yet because we have some good news for you!

Fine matcha can clump

Matcha is a whole tea leaf ground into an ultra fine and delicate powder which creates static in the tin and naturally cling together during storage, packing and travel. Clumps alone don’t indicate poor quality. Fresh matcha should feel soft and powder, with clumps that break apart easily when sifted.

A sign of High Quality

Surprisingly, tiny lumps are often considered a sign of high quality rather than a spoiled poor quality product. High grade matcha is often milled using an (ishu usu) 石臼 - traditional Japanese stone mill made of two interlocking granite discs. A traditional stone mill can only produce only about 30-40 grams of stone ground matcha per hour. Granite stone mills rotate slowly at roughly 50-60 revolutions per minute. This deliberate pace yields an ultra fine powder with a particle size of about 5-15 microns. That is why stone ground powders usually cause a lot more clumping than modern machine milled matcha. This causes the particles to cling together via static, moisture, humidity or natural compaction.

A quick sift can change everything

These clumps should feel light and powdery, breaking apart easily when sifted. While clumping alone isn’t an indicator of quality, finely milled and fresh matcha is more likely to form soft, dry clumps with a delicate, powdery texture. Look out for clumps with a grainy and gritty texture.

The Paste Method to the rescue

Sifting matcha before brewing does help. It breaks up clumps and makes the powder easier to dissolve evenly. But, it is not the only way to achieve to a lump-free brew. The matcha paste method is more effective in practice. Start by adding 10ml water to 3g matcha and knead it in a circular motion to make a paste before adding the remaining water to whisk. This eliminates the tiniest of clumps.

What to look out for?

Clumpy matcha, by itself is not a sign of poor quality. What matters is what comes with it. Clumps accompanied by a dull or brownish colour, stale odour, coarseness or a gritty grainy texture can indicate that the matcha has lost its freshness. Fresh finely milled matcha should feel soft and powdery, with clumps that break apart easily when sifted. 

Conclusion

Matcha doesn’t fully dissolve like instant coffee or sugar. It is whole leaf tea ground into a fine powder, so the formation of clumps are certainly evident, especially over time. This is completely normal, particularly with stone-milled matcha. So the next time you find clumps in your matcha, don’t assume it’s bad. Look at the signs as a whole, not the clumps alone.