View Full Version : Mead Spoiling?

Andy H
11-25-2004, 05:08 AM
Well, i'm into my second batch, the first tuned into a disaster with 3 gallons spoiled (i almost cried when i had to pour it down the drain)

now i'm getting the same problem with my second batch. Please note that anything that touches my Mead is sterilized with Meta-bisulfate or chlorine bleach solution.

now for the problem;

Just after secondary(Finings just added) i had found a grey film formed on the very top of my mead, and produced a foul odor.

getting that 'not-again' feeling(as this is what had happened, but worse to my first batch), i ran to the local brew shop to buy some more materials and promptly sterilized all my equimpent and filtered out into another carboy, leaving all traces of this grey film in the first carboy.

now, to try and salvage ther rest of the batch (which nosed fine, and tasted perfectly normal; and very good) I started the batch again.

1/2lb honey
1/3lb Dextrose
1 tblsp Dibasic amonium phosphate
1 tsp and a bit Acid blend
1 package Champaigne Yeast(only stuff the local shop carried)

now as there is nothing currently wrong with the rest of the batch, i'm hoping that by cultivating a healthy yeast population and upping the alchohol (from 8% to 16%, ale yeast to champaigne) i'll kill off any remaining traces of the mystery offender.

now, this little trick worked for another hobby brewer i know who had a bad batch of white wine, and it turned out fine as high-test wine.

will this work for mead or will i be out of luck?

11-25-2004, 05:48 AM
Sounds to me like an Asperillis infrection of the top film. Somehow you're getting contaminant spores entering the mix. How are you containing and sealing your batch?? I did have this on my first batch (which was an open bucket with a cloth over it as per ye olde vikings) and simply skimmed it.

As AFAIK it is aerobic and therefore only on the surface. Others might contradict me on this, but my humble advice is to simply skim generously until you get all of the clumps out and re-rack in sterile containers, and make sure it is sealed and the seals are also sterilised.

People drinking the first batch are all still alive ;D

Andy H
11-25-2004, 04:22 PM
Asperillis? hmm, i've only ever seen it once before in biology class. unless i'm mistaken it's a bacterial infection(only got a 72% in biology :( ). but just to make sure. it produces a sulfur odour (rotten eggs) correct?

i'm not a newb to brewing, so i keep everything very sterilie, and am using an air-locked (meta-bisufate solution in the airlock!) 20L glass carboy. the food grade pail i usually use is beeing used for the racing intermediary in this batch.

well, i'll just have to add some poassium sorbate to the mix soon, it's been aobut 1 1/2 days and the champaigne yeast seems to have run it's course. no viloent fermentation though, and no bubbles. i think the yeast may have been a dud though.

i'll check back in another day.


11-25-2004, 11:45 PM
If i'm not mistaken you guys are talking about Aspergillus which is a fungus and is an extreamly common household contaminant.

It seems that somewhere along the line your batches are becoming contaminated. Now its time to start playing a bit of detective and figure out where its comming from. How are you preparing your must? are you sanitizing the must itself in any way? Are there any fans on or windows open when you are preparing it? just a few things to think about as possible sources of contamination.

11-26-2004, 12:14 AM
That doesn't sound like Aspergillus niger to me. A. niger forms ooid or circular dark gray colonies with a whit-ish colored center, especially in food. Penicillium sp. generally forms a white colored colony with a green center and the colonies have lines radiating from the center of the colony to the outside like a wagon wheel.

Can you identify the foul smell? Is it like vinegar, sulfur, musty, etc.?

Can you describe how you're sterilizing, and the strength of the sterilization solution you use?

Can you also describe the environment? Are you close to any grain silos, feed pens, poultry farms, fish hatcheries, etc.? Do you brew in an enclosed or open area, and do you dust and mop before you brew?



edited for spelling

Andy H
11-26-2004, 01:28 AM
Always clean everything, and i mean everything, that comes into contact in any way with the must or brewing equipment(the brewing equipment is thoughly cleaned).

I commonly use a solution of meta-bisulfate, the ratio is usually around 25g for every 2L of water. i've taken to using a solution of half a cup of Chlorine Bleach in 4L of water for any Glass equipment. All equipment is sterilized just before it is used and thoughly rinsed in clean, running, cold water.

When I sretilize my carboy it is never more than 15 min before i start making the must, and it is serilized, rinsed and then airlocked using a solution of 1/6tsp Meta-Bisulphate to around 1.5 fl. oz. water.

there are no open windows when i brew, and i like to mop using a hot water and anti-bacterial floor cleanser about 1h before brewing. I never brew when the place has been swept in the last 16 hours.

as for the grey film, it did show signs of colonization, white arms radiating from a center in one or two places, but very small. the odour it gave off was of sulphur. (who can mistake that smell?) beneat the initial hit of sulphur, there was an organic (but not 'musty') note to the smell.

11-26-2004, 01:59 AM
Good information Andy, thanks.

Let me ask a couple more quick questions, sorry for the continued interrogation.

Do you cover your carboy before you fill it? That is, do you cover the mouth of the carboy with a sanitized bit of plastic wrap or a cap or something to keep any airborn contaminants out?

I was unsure from your posts if you switched to an ale yeast from the champagne yeast or not. Some ale and lager yeasts will produce a notable sulfur smell. Also, take a sample from your carboy from a few inches below the surface and taste it.

If it is OK you can skim the surface, or maybe better rack it to a clean sanitized carboy and leave a couple of inches with the mold floating on top.



11-26-2004, 03:48 AM
Well, it does sound like my first batch, which when I first discovered the problem, was grey and powdery in look, with a sulphuric smell. Oskaar, you sure it isn't Aspergillis (which I meant)? My samples were IDed as such, forming assymetrical colonies and floating in clumps.

Several skimslater, the brew was okay and drunk in due course with no noticable change to flavour, though reduced in quantity after liberal skimming with the elimination of the spores.

11-26-2004, 05:50 AM
It very well could be A. niger, but from Andy's initial description of a grey film on top of the must it didn't seem like it. The later description sounds more like Penicillium sp, but there's no real way to know without seeing it and doing a culture to track down the beast.

Aspergillus forms an aflatoxin that is somewhat alcoholic too, so I'd be curious to see how Andy's stuff tastes a couple of inches below the infection, whatever it is. Your description of the asymmetrical colonies is consistant with the morphology of Aspergillus colonies as well, though they tend to be roughly circular, oblong, ooid, etc. The reason I was asking him about the grain silos, feed lots, etc. is because those are common breeding grounds for the Aspergillus and many other molds, yeasts, and other foul beasties.

Blast, I just noticed I misspelled Aspergillus in the first posts I made.

Maybe Andy could shoot a photo and post a link to it for us. That would be helpful.


11-26-2004, 07:27 PM
Well, the upshot of my own experience is that the must was salvageable after some skimmings, and has produced a pleasant brew (the one I bottled too early and went fizzy).

11-28-2004, 05:29 AM
Is it possible that the source of the contamination is the dextrose?

Was the dextrose boiled in water?

11-28-2004, 06:12 PM
Why are you using dextrose to begin with?

I've personally found that the simpler you keep your recipe, the more successful it's going to be.

Andy H
11-29-2004, 06:53 AM
I'm using dextrose because ;

a) I'm cheap

b) and the honey i have is very flavourful (nice, nut brown purple loostrife (sp?) )

the next answer is yes, everything that is added to the must is sanitized in some way. the dextrose surup that i make is boiled, and hits aprox 120C before it tis taken off the heat.

I found the source of contamination anyways. someone (can't say for sure who) had taken a look at it, and uncorked the carboy, forgetting to replace the cork(airlock).

11-29-2004, 08:29 AM
Hmmm, time to set up a webcam!

Do you have cats, or an overly curious next door neighbor, or a monkey (OK neighbors and monkeys can be difficult to distinguish but you get the idea)?

Anyhow, glad the mystery is solved.

Brew HA HA!


David Baldwin
11-29-2004, 04:59 PM
Would metabisulphite kill an aspergillus or penicillan infection?