# Moldy corks after storing wine on their sides



## pandakatelyn (May 10, 2021)

I kept some bottles (ranging from dec '20 to march '21) on a wine rack in my dining room, and popped open one today to discover mold on the cork. 3 other bottles were also molding. I use star-san sanitizer and am immaculate about cleaning. How do i prevent this? Was it because I stored them on their sides? The corks themselves? I'm kicking myself because now I have to dump 10 bottles.


----------



## crushday (May 10, 2021)

A couple of questions:

1. Did you make this wine or is it commercial?
a. If you made the wine, then question #2...
2. When you bottled it, did you let the cork ”seat” by storing upright for 2-3 days before laying the bottles down?

Either way...

3. What’s the temp of your dining room? I suspect the real culprit is ambient temperature warming the wine in the bottles, which causes it to expand. The now expanded wine has nowhere to go and will find the path of least resistance. Small amounts of wine are exiting the bottle around the cork and molding under the cap, which is a low light environment - perfect for mold.

And, I think dumping the bottles is not necessary. Mold entering the bottle is a near impossibility, IMHO. Clean them up and drink the wine...


----------



## pandakatelyn (May 10, 2021)

crushday said:


> A couple of questions:
> 
> 1. Did you make this wine or is it commercial?
> a. If you made the wine, then question #2...
> ...



I made it, and let it sit upright for 5 days before storing laying down. The ambient temp is usually around 67-70. I also use heat-shrink capsules on my bottles.


----------



## crushday (May 10, 2021)

How much head room do you have between the wine and the cork? I still suspect expansion and contraction from ambient temperatures. 

You probably do this too... After I bottle, I store upright for a couple of days and wash/rinse the filled bottles before capping and labeling. 

And, I think dumping the bottles is not necessary. Mold entering the bottle is a near impossibility, IMHO. Clean them up and drink the wine...


----------



## crushday (May 10, 2021)

And, your corks - are they size #7, #8 or #9? #7s are going to allow more ‘blow by‘ than both #8 and #9, the latter being less susceptible.


----------



## pandakatelyn (May 10, 2021)

crushday said:


> How much head room do you have between the wine and the cork? I still suspect expansion and contraction from ambient temperatures.
> 
> You probably do this too... After I bottle, I store upright for a couple of days and wash/rinse the filled bottles before capping and labeling.
> 
> And, I think dumping the bottles is not necessary. Mold entering the bottle is a near impossibility, IMHO. Clean them up and drink the wine...


 I leave quite a bit of space, I think. I usually spray everyone down with a star-san mixture and dry before capping. This is one of the bottles I've had since Jan. One of my dragonsblood was a goner, it had a mold bit floating in it. I'm wondering if its the corks, since I tried a new brand this time around from amazon.


----------



## pandakatelyn (May 10, 2021)

crushday said:


> And, your corks - are they size #7, #8 or #9? #7s are going to allow more ‘blow by‘ than both #8 and #9, the latter being less susceptible.


I am using #8 corks and a portuguese floor corker.


----------



## crushday (May 10, 2021)

Wow. I see what you mean now. There’s a couple firsts for me in your images:

1. The agglomerated corks have very large bits and pieces. 
2. I’ve never seen mold visually embedded in the cork.

Without a doubt, it’s the corks. Because of the size of the pieces making up the cork, there’s undoubtedly lots of space for mold to hide.


----------



## pandakatelyn (May 10, 2021)

crushday said:


> Wow. I see what you mean now. There’s a couple firsts for me in your images:
> 
> 1. The agglomerated corks have very large bits and pieces.
> 2. I’ve never seen mold visually embedded in the cork.
> ...


That was my suspicion! I had just started to use these corks. Time to chuck 'em and start again.


----------



## MiBor (May 10, 2021)

I started using synthetic corks exclusively (Nomacorc only) after a couple of embarrassing events when friends I gave wine to said my wine was awful. I managed to find that the problem was the corks I used that year after uncorking about 20 bottles and finding 3 that smelled bad. I don't like the look of the 1.5 inch synthetic corks, but I managed to find #9 Nomacorc in 1.75" length and I never looked back. I know that a wine bottle looks more classy with a natural cork, but I don't want to worry about wine going bad in the bottle again. Plus I can store the bottles upright without fear of corks drying out.
Here is a link, in case you want to check them out:
WINE CORKS 100 SYNTHETIC NOMACORC SELECT 900 WOOD GRAIN FINISH #9 1-3/4″ 22mmX44mm Champfered - Hobby Homebrew


----------



## bstnh1 (May 11, 2021)

I've used the bi-disc corks from Widgetco for years with no issues at at. I've recently started using Nomacorc just for the convenience of being able to store them upright. I have always used No 9 corks. My take on Amazon - there are a lot of bogus items and other junk being sold on Amazon. There are companies who refuse to sell on Amazon and will not honor a warranty if their product was bought there. I think you'd be safer getting your corks from any brew shop.


----------



## Rice_Guy (May 11, 2021)

For mold to grow it requires 1) oxygen, 2) humidity, 3) food source 4) mold spores

* You mention shrink caps which trap humidity. If the caps are removed the problem should go away
* you are using natural cork which leaks (inward rated 4 to 8 mg oxygen per year) why not use synthetic corks which are tighter? and prevent egress or ingress and eliminate both humidity and food source


----------



## winemaker81 (May 11, 2021)

@pandakatelyn, I've been using Nomacorcs for about 3 years, the Select 900 1.5", and really like them. I had mold problems on the outside of the cork -- it's not dangerous, but it's very unsightly and makes an instantaneous bad impression. Nomacorcs solved that problem.

From what I gathered from the Nomacorc fact sheet and other sources, the Select 900 should be good for 5+ years, and they are the most common model I've found.

*This thread* has a lot of information regarding Nomacorcs. Some folks report synthetic corks getting creased by Portuguese floor corkers -- I suggest buying a small bag and seeing how yours works.

Personally, I don't use #8's, as I've had leakage in the past. The inside diameter of bottles is not uniform, and IME #9's have worked in all standard wine bottles.

Also, corking screwcap bottles is hazardous. The neck is not designed to handle the stress of corking, and bottles may shatter, so use only corkable bottles.


----------



## Raptor99 (May 11, 2021)

I use natural corks and I soak them in Kmeta sanitizing solution for 15 minutes before inserting. That softens them up and also sanitizes the corks.


----------



## hounddawg (May 11, 2021)

i use normacroc select #9 that are 1&3/4 i still have some dated 2014, and the rest i use natural Flor corks, of which I'm going to start using nomacroc reserva instead of Flor
Dawg


----------



## stickman (May 12, 2021)

In 30yrs I haven't seen mold on corks like that. The wine should not soak into the cork a third of the way to the top in less than a year. There are disturbing reports of arts & crafts corks being sold on Amazon as "wine grade", buyer beware applies more now than ever, stick with reputable suppliers for best results.


----------



## pandakatelyn (May 20, 2021)

I bought synthetic from a local supplier and had great results. No more Amazon corks!


----------



## hounddawg (May 20, 2021)

IMHO,, normacroc are the only way to fly
Dawg


----------



## Raptor99 (May 20, 2021)

hounddawg said:


> IMHO,, normacroc are the only way to fly
> Dawg



I may have to try those. I am currently using #8 natural corks with my hand corker like this one: https://www.amazon.com/Home-Portugese-Double-Level-Corker/dp/B000FRWJNE/ Do they make #8 normacrocs? I'm not sure that I can use #9 corks with my hand corker.


----------



## Gene Kimmi (May 20, 2021)

I have that exact corker and have used many of the #9 normacorcs with it.


----------



## bstnh1 (May 20, 2021)

Raptor99 said:


> I may have to try those. I am currently using #8 natural corks with my hand corker like this one: https://www.amazon.com/Home-Portugese-Double-Level-Corker/dp/B000FRWJNE/ Do they make #8 normacrocs? I'm not sure that I can use #9 corks with my hand corker.


I have a Portuguese floor corker now, but before that I used the same corker you have with No. 9 regular corks and No.9 Nomacorcs.


----------



## hounddawg (May 21, 2021)

Raptor99 said:


> I may have to try those. I am currently using #8 natural corks with my hand corker like this one: Amazon.com: Portuguese Double Lever Corker: Kitchen & Dining Do they make #8 normacrocs? I'm not sure that I can use #9 corks with my hand corker.


yes they make about any nomacroc you could want, i use to use a lower end cork for whites and Flor for reds, i talked to,,i think it was Steve @vacuumpumpman , whom told me he used nomacrock for quite a spell, I've never looked back,, got some and that has been several years now, store standing or laying on side, dont matter, i got some melomel that's 2014 been sitting up since day one most are gone but about a month ago i pulled a cork, good as ever,
Dawg


----------



## Rice_Guy (May 21, 2021)

The Nomacorc is produced with a smooth slide surface on the outside. They are significantly easier to push in than natural corks.


Raptor99 said:


> I may have to try those. I am currently using #8 natural corks with my hand corker like this one: https://www.amazon.com/Home-Portugese-Double-Level-Corker/dp/B000FRWJNE/ Do they make #8 normacrocs? I'm not sure that I can use #9 corks with my hand corker.


The double lever I have has a small diameter push rod which produces a cosmetic divot on the surface.


----------



## Sailor323 (May 21, 2021)

I have wine in my cellar that is 20+ years old. Nearly all of the bottles have mold on the corks but that does not affect the taste of the wine. The corks are 13/4 inch natural corks. The only problem that I occasionally run into is the the corks can be somewhat crumbly and removing them can be difficult


----------

