White Mould

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White Mould

Postby ginandtonic » Wed Feb 04, 2026 4:56 pm

IMG_8931.HEIC.pdf


I have just discovered some white mould in one of the 2 x 25 litre fermenters I have going.
One has a very suss mould growing on the top - the other does not, mind you the one that does, is the one I have opened a few times to check fermentation.
Each batch is 5kg Coopers wheat malt, milled, about 15 litres boiling water ( even though I am using angel yellow label - kind of think that may help ? )big stir with s/s drill powered mixer,
Topped up to 25 litres, and when temp drops to 30 - pitch 40-50g of yellow label, plenty of stirring during this process. I then wrap in blankets, heat belts at 30 degrees, and start the wait.
I give a good mix the next 2 days.
I have done this process with rice on a few occasions and never any problems ( maybe Ive been lucky ) - this is my first grain venture
But 20 days in, just opened and while one looks good, and is very close, the other looks SUSS.
Anybody ????
Thanks in advance.
Gin and Tonic
PS - can definately recommend anyone to try a rice wash - has produced clean neutral !
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Re: White Mould

Postby The Stig » Wed Feb 04, 2026 5:39 pm

Does it look like this pic ?
If it does it’s likely a lactose infection
It’ll be fine , let it finish and run it
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Re: White Mould

Postby TheRealMrMessy » Wed Feb 04, 2026 6:12 pm

Could also be Kahm yeast. I often get Kahm in my ginger beer brews - hard to totally prevent wild yeast with some blends.

Long as it doesn't go various colours of the rainbow or get fuzzy, you're probably fine.
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Re: White Mould

Postby ginandtonic » Wed Feb 04, 2026 6:18 pm

Yes Stig, Thats the one !
Is it because Im not being as careful / clean as I should ?
Is there a certain time ( ie 2 days ) after which I should not open the lid to stir etc
It may be harmless, bit id rather not have it :o
Many thanks
Love your work Gents ^:)^
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Re: White Mould

Postby bluc » Sun Feb 08, 2026 2:26 pm

Hard to keep lacto out if you dont like sourness add sodium per carbonate(home brand no scent napisan) to your cleaning schedule between mashs..
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Re: White Mould

Postby bluc » Sun Feb 08, 2026 2:28 pm

Longer ferment sits once the white stuff is on top more sour the flavour to a point.
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Re: White Mould

Postby TheRealMrMessy » Sun Feb 08, 2026 6:57 pm

I also intentionally added lacto previously, doing sour mash bourbon :handgestures-thumbupleft: . Corn and rye 80/20 mashed with added enzymes, soured for 6 days then fermented and came up great. Lot of work to mash all that damn corn, glad I sprung for stuff already gelatinised.
Last edited by TheRealMrMessy on Sun Feb 08, 2026 6:57 pm, edited 1 time in total.
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