What's growing on my Christmas pudding?!
December 23, 2022 9:27 AM Subscribe
Back around March/April this year I made two Christmas puddings from scratch. We ate one at the time and saved the other (a mistake, I now realise). Checking on it today, we found the pudding has developed some kind of weird dusty substance on top. What is this stuff?
It's kind of sand-coloured and looks a bit like sand, though the texture is powdery to touch. The brown stuff doesn't look like any kind of mould I've ever seen, though the white flecks kind of do. The photos above were the best I could do with my phone camera and our kitchen's sub-optimal lighting.
I used this recipe and missed the instructions at the end to freeze it and eat it within a year of freezing, and to only keep it in a storecupboard for up to six weeks. I also missed out the sugar from the original recipe by accident, in case that's relevant.
To be clear, I'm not looking for general advice on how to not fuck up making a Christmas pudding in future, or about what I should have done differently to avoid this outcome. And we are absolutely not going to eat it. We have several store-bought puddings laid down just in case, and Christmas is not ruined.
I just want to know what this substance that's grown and/or extruded out of my pudding is, given that I've never seen food go bad in this particular way before.
It's kind of sand-coloured and looks a bit like sand, though the texture is powdery to touch. The brown stuff doesn't look like any kind of mould I've ever seen, though the white flecks kind of do. The photos above were the best I could do with my phone camera and our kitchen's sub-optimal lighting.
I used this recipe and missed the instructions at the end to freeze it and eat it within a year of freezing, and to only keep it in a storecupboard for up to six weeks. I also missed out the sugar from the original recipe by accident, in case that's relevant.
To be clear, I'm not looking for general advice on how to not fuck up making a Christmas pudding in future, or about what I should have done differently to avoid this outcome. And we are absolutely not going to eat it. We have several store-bought puddings laid down just in case, and Christmas is not ruined.
I just want to know what this substance that's grown and/or extruded out of my pudding is, given that I've never seen food go bad in this particular way before.
Response by poster: The best nose in the house (mine) does not consider the pudding palatable. It doesn't smell good, or the same as it did when it was fresh, and it doesn't smell like sugar. The smell gives me 'don't eat this' vibes, hence the decision to toss. Regarding immune systems, guests are all healthy but one is in their mid-70s and I don't want to take risks on their behalf. And this isn't a 'can I eat this?' question ;).
Also, the texture of the substance when crushed is powdery, and not at all like crystallised sugar . There's no crunch/crush to it when it's squeezed between fingertips and no graininess when rolled between them, both of which I'd expect from extruded/crystallised sugar. And it's not sticky at all.
posted by terretu at 10:26 AM on December 23, 2022 [1 favorite]
Also, the texture of the substance when crushed is powdery, and not at all like crystallised sugar . There's no crunch/crush to it when it's squeezed between fingertips and no graininess when rolled between them, both of which I'd expect from extruded/crystallised sugar. And it's not sticky at all.
posted by terretu at 10:26 AM on December 23, 2022 [1 favorite]
Best answer: I am not a mycologist, but to me, that really looks like some sort of yeast or mold.
Edited to say I think it could be Wallemia sebi, a type of mold that loves sugary things.
posted by easy, lucky, free at 10:33 AM on December 23, 2022 [5 favorites]
Edited to say I think it could be Wallemia sebi, a type of mold that loves sugary things.
posted by easy, lucky, free at 10:33 AM on December 23, 2022 [5 favorites]
I have no special training, but I would call that mold and throw it the heck out
posted by chocotaco at 10:33 AM on December 23, 2022 [3 favorites]
posted by chocotaco at 10:33 AM on December 23, 2022 [3 favorites]
Data point - my British aunt re-moistens her (year old) puds with booze on the regular, maybe that's the trick.
posted by stray at 10:41 AM on December 23, 2022 [1 favorite]
posted by stray at 10:41 AM on December 23, 2022 [1 favorite]
I think it's probably a different fungus, but possibly of interest: There have been Twinkies that went quite moldy with Cladosporium cladosporioides while still in the packaging.
posted by cnidaria at 12:30 PM on December 23, 2022
posted by cnidaria at 12:30 PM on December 23, 2022
Best answer: That looks a lot like Alternaria cultures from my plant pathology days (although there may be a couple things in there and I’d need spores to tell for sure). Freezing would prevent this and other molds. I was all prepared to say that it’s just sugar, but it’s really really not.
posted by momus_window at 12:32 PM on December 23, 2022 [2 favorites]
posted by momus_window at 12:32 PM on December 23, 2022 [2 favorites]
You forgot to put the sugar in? With a heavy heart I suggest that you need to throw this away :( I don't think the dried fruit by itself has enough sugar to preserve the pudding properly so it's grown some kind of fungus, as per other answerers. My condolences, I am aware how expensive dried fruit is!
posted by altolinguistic at 3:50 AM on December 24, 2022 [1 favorite]
posted by altolinguistic at 3:50 AM on December 24, 2022 [1 favorite]
Slight aside: I knew sugar is a preservative, but I realised I didn't know why it's a preservative. So I googled. The BBC's Science Focus has the answer!
Basically: both sugar and salt attract water. Bacteria evolved in environments where the concentrations of sugar and salt outside their cells matched the concentration inside their cells. But if you add lots of salt or sugar to food, it sucks the water out of the bacteria via osmosis and they can't grow.
posted by davidwitteveen at 12:39 AM on December 25, 2022
Basically: both sugar and salt attract water. Bacteria evolved in environments where the concentrations of sugar and salt outside their cells matched the concentration inside their cells. But if you add lots of salt or sugar to food, it sucks the water out of the bacteria via osmosis and they can't grow.
posted by davidwitteveen at 12:39 AM on December 25, 2022
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I'd eat it.
posted by scruss at 9:59 AM on December 23, 2022