Hmmm, mould

I was examining the few cakes I have here that I keep as “taster” cakes, and noticed something funny — one of them, namely the Fuxing Zhangjiawan, has a little bit of mould on it.

It’s been pretty rainy here the past few weeks and I have paid very little attention to these cakes. In fact, I haven’t really bothered with them for a while now, and have just left them alone. I looked at all the cakes I have in the same area, in my living room (the non-taster stuff are kept up in a little loft). It seems like the Zhangjiawan is the only one with any noticeable mould. I think this makes sense. The Zhangjiawan was covered by the other cakes, and sat at the bottom of the pile. I suppose what happened is that any moisture accumulated in it was not easily dissipated, and so whereas the other cakes dried out a little when the weather turned drier, the Zhangjiawan never did. None of the other cakes had a problem, and the ones up in the loft do seem a little drier — I suppose moisture is heavy.

The other thing is that the mould is growing in one paritcular type of place on the cake — at the end of the stems. They’re not all over, nor are they on the leaves. They are at the end of the stems where the leaf was plucked. Could it be that the stems retain moisture the best, and therefore makes the best place for mould to grow?

YP told me that she noticed that aged oolongs are often very sour when it was never de-stemmed. She thinks the stems do retain moisture better and thus turn the tea sour faster. Perhaps the same effect is seen here?

Either way, this is pretty interesting. I am almost tempted to let the mould grow uncontrolled and see how the cake fares in a month’s time. But then…. maybe I should let it dry out a bit. I only have one cake of this with me now, and I’d rather try it as it ages slowly.

I think I made the right decision to store my tea in Hong Kong on shelves that are near the ceiling rather than near the ground.


Comments

Hmmm, mould — 5 Comments

  1. Biologically speaking, the stem is going to be chemically different than the rest of the leaf. It will also retain moisture longer since it is thicker.

    Chemically, plants produce substances in reaction to damage. Kinda like the oriental beauty and leaf hopper thing but more localized. When you cut most plants, they run sap to the damaged area. Sap will have lots of things in it including sugar. So when the plant bleeds, that blob of sap will form a small pool of nutrients.

    The rest of a leaf will have a skin, and a wax, so it’s not surprising to me that the stem tip would mold first except for tiny pores in the plan leaf that’s used for o2co2 exchange. I think when you see the golden flowers, they’re growing in a pore, but I haven’t looked at it under a scope, so that’s speculation. Anyway, the stem tip has the least protection on the surface from “germs” and also has a higher concentration of nutrients.

    It’s also why plants tend to have a different type of tissue where the stem attaches to a branch, so that when trees that lose their leaves for the winter shed their leaves, it doesnt expose the tree to “germs”. But of course tea trees dont lose their leaves.

    Anyway, I think what you observed is completely logical.

  2. The rest of a leaf will have a skin, and a wax, so it’s not surprising to me that the stem tip would mold first except for tiny pores in the plan leaf that’s used for o2co2 exchange.

    Plan leaf?

  3. The stem is composed of phloem tubes that transport moisture–this is how plants transport water and nutrients up to the growing shoots from the roots, so yes, the stems dry last and hold residual moisture within the tubes that make up the stem

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