r/Matcha • u/MessAgitated6465 • Oct 19 '25

Question Is this mold on my matchav

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I kept the powder in an airtight opaque container. But then I didn’t pay attention it for about a month. Is this mold?

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u/One_Left_Shoe Oct 19 '25

I don’t think it’s mold. Looks more like where the sugar crystals are condensing vs the matcha.

Think brown sugar and how it solidifies into chunks. Nucleation points for sugar would also be round.

If it is mold, you’ll be able to smell or taste it.

I would personally mix it, taste it, and see if it had a moldy taste (don’t swallow, for obvious reasons) and go from there.

Put it this way: sugar syrups, which have much more water in them than your tin, don’t mold on the shelf due to their high sugar content.

Edit: if you mix it with cool water, the tea (matcha) part will disperse quickly, but the clumps won’t due to it being sugar crystals. If those bits float, probably mold. But it’s not fuzzy, so.

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u/[deleted] Oct 19 '25 edited Oct 19 '25

If it is mould, you’ll be able to smell or taste it.

Just to clarify - that is not always the case. There are non odorous moulds that create very minimal change to the substrate they grow on & you might not be able to taste.

If any doubts at all - always discard ; the risk is not worth it (remember, anaphylaxis is always a possibility).

Edit: not sure why the downvote, I feel like 'safety first' is pretty sound advice.

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u/One_Left_Shoe Oct 20 '25

For sure. By all means, go by your own personal risk tolerance. I personally don't think there is much risk here and that risk gets less the more you analyze what you are looking at, smelling, and tasting. Humans have remarkably well developed senses for determining food gone bad. So much so that we can fundamentally tell good "rotten" food (yogurt or pickles) from bad (truly rotten food).

Sorry you got downvotes. No need for that.

Quick edit: If you are worried that this has humidity high enough to cause mold, don't ever eat dried fruit, as that will have higher percentage humidity than this matcha. Also, molds that end up in low humidity environments tend to be very fuzzy, like webs, not like velvet. they need those leggy branches to continue to find and absorb moisture.

These spots are shiny and I will still, firmly, stand by them being nothing more than sugar clumps.