View Full Version : Moldy corks?

02-15-2010, 12:03 PM
I ran into a new problem over the weekend and wanted to get some advise. I bottled a traditional mead on 1-24-10. there were no sulfites or campden used before bottleing.
I was planning on drinking all of it in less than a year.

My process was:

1- I filled a bucket with a idophodor solution and sterilized 2 bottles at a time soaking them for 3mins each. when done they were immediatly filled and corked.

2- all the corks were soaked in the same solution durring bottleing and removed only when I could cork a full bottle.

3- bottle was placed in a floor corker and corked. (I cleaned the corker with hot water and wiped it down with a Idophodor soaked cloth.)

4- I left the bottles upright for 72 hrs to let the pressure escape.

5- after the 72hr wait i placed all the bottles in a dark case on there side to age.

My question is when I checked them over the weekend I noticed that on the bottom of the coarks there was a black covering over them, some had the black "coating" traviling up the cork but not to the outside of the bottle. None of them were leaking.

The corks were all brand new from my local HBS, the corks were size 9 1-3/4" mulit piece construction "not the corks that are cored from a solid piece of cork"

Is this normal? Are the contents still drinkable? What caused this problem and how could i avoided it in the future?

p.s. I can provide pictures if needed.

Medsen Fey
02-15-2010, 12:48 PM
p.s. I can provide pictures if needed.

Please do - that may be helpful.

02-16-2010, 11:23 AM
Here are some of the better pics i could get. I must have taken 200 pics and none of them showed the cork all that well.

Hope this helps

02-16-2010, 11:47 AM
These are too fuzzy to say anything definitive about what's going on. The color suggests mold, but I can't tell for sure. I'd say, under the circumstances, pull one of the nastier looking corks and check it definitively for mold. If you catch it early enough you can open all the other bottles, treat your mead with sulfites to kill off any mold spores that are in there (you don't even need to pour out the mead and re-bottle, but you can if you want to), rinse any new corks that you will use with a fairly concentrated solution of metabisulfite with a little acid blend added (the acid blend lowers the pH of the rinse water, which will help to activate the sulfite), and then re-cork.

Medsen Fey
02-16-2010, 11:48 AM
I can't see the cork well enough to say much from the pictures. Have you pulled one out to examine it closely?

02-16-2010, 12:57 PM
I havent done anything to them yet. The bottles are crystal clear so I can see the cork well just cant get a good pic. It looks like the cork itself is turning black no fuzz on it but the cork has been wet the whole time.

As to the sulfite treatment what would you suggest I have about 12 bottles of the 750mm that all need to be treated. a quater tablet each?? there is only one bottle in this batch that doesent have the "mold" and that bottle has been upside down (cork on the bottom) due to some yeastys that got in there, I was planning on freezing the cork and pulling the plug on it.

How would i be able to tell if it is mold? Hairs?

02-16-2010, 04:27 PM
Most mold colonies will form tendrils after a time, but if you do pull a cork to examine the black stuff more closely, sniff at it and touch it with your finger. Mold, as well as other spoilage organisms, will generally smell bad (spoiled or "musty") and feel slightly slippery to the touch.

To add a measured dose of sulfite to each bottle, it is better to mix up a bulk solution that when a measurable amount is added to the mead in each of the bottles, will dose each with an amount equivalent to 100 to 150 ppm free SO2. Measuring out the correct amount of tablets or powder to add to each bottle individually would be too difficult.

So, let's run through a little calculation to see how much you'll need. You have 12 bottles that need to be dosed, and each one contains about 750 ml of mead. You can probably add another 5 ml of liquid to each bottle and still get a cork in with no problem, so let's assume the total volume in each bottle will be 755 ml after you make the addition. NOTE: 5 ml is not a lot - it is almost exactly 1 level teaspoon.

Anyway, back to the calculation. Let's assume that your mead is a nominal pH of 3.5, so you want (for the sake of argument) to get 100 ppm of free SO2 in each bottle, but you should assume that some amount of what you add will be "bound" by other compounds in the mead. So, let's shoot for a total addition of 150 ppm to each bottle. Conveniently, one part per million is the same as 1 milligram per liter, so 150 ppm is 150 mg per liter. Since you will have 0.755 liters of liquid in each bottle, you'll want to add 0.755*150, or 113.25 mg of SO2 to each bottle. Assuming you are using potassium metabisulfite which is 57% SO2, you'll want to add 113.25/0.57 = 198.68 mg of K-meta powder, or the equivalent in campden tablets, per bottle.

Call that 200 mg just to do everything in round numbers. Making up a solution good for 12 bottles, take 200mg * 12 = 2.4 grams of K-meta powder, and dissolve that completely in 5 * 12 = 60 ml of water. Then take one tsp of that K-meta solution and add it to each bottle shortly before you cork them with new corks.

02-16-2010, 05:14 PM
All i have availible at the moment is campden tablets.
assuming 1 tablet is eq. to .44 grams i need 6 tablets to make 2.4 grams
60ml of water is equil to .25 cups of water

I think i have my math wrong can anyone help?

Medsen Fey
02-16-2010, 06:10 PM
The math looks right.

You definitely need some new corks - in this case I might suggest synthetic or Zorks.

02-16-2010, 06:38 PM
2.4 grams of metabisulfite = 5 & 1/2 tablets. Cutting them isn't the easiest thing to do, but you can do it by hand close enough if you use a boxcutter or single edge razor blade. Close to half is good enough. If you don't want to mess with cutting, using six will give you slightly more sulfite per bottle but that won't hurt anything.

60 ml of water is 12 teaspoons, or 4 tablespoons, or a quarter of a cup.

02-17-2010, 03:57 PM
I went out last night bought some new synthetic corks and k-meta powder. (no computer at home so i missed the replys). Everything worked out well It looks to me like the corks that I used were bad to start with. The mold was growing inside the corks probablty activated when they got wet, There was no off smell to them but the mold had just broken the surface.The corks are the multi-pieced and glued together I wouldnt reccomend useing that type after dissassembleing one.