Madeira melted my Rabbit wine stopper. What do you use?

Hi everyone,

I opened a bottle of Rare Wine Company Charleston Sercial Madeira about 6 mos back. I’ve been taking small pours from time to time ever since. I used a rubber Rabbit wine stopper as a closure in the meantime. I emptied the bottle tonight, put the stopper on the counter, and noticed that the portion of the stopper that was in the bottle was discolored and the tip seemed to have melted a bit. The discolored portion felt softer, stickier, and even after rinsing off with water smelled strongly of Madeira.

My guess is that the alcohol fumes from the nearly 20% ABV wine deteriorated the stopper over time. But is that possible?! Seems crazy since this product is meant to seal bottles of alcoholic beverages. Have I been unknowingly imbibing bits of melted plastic along with my Madeira for the past 6 months?! Yikes!

I have a bunch of Rabbit stoppers, but I’m not getting any more. And now I’m probably going to be getting rid of the ones I have. So I’m curious if you have any other recommendations for closures that will last on the order of months, especially to close bottles of higher ABV stuff like Madeira and older spirits with dried/crumbled corks.


Not knowing of the chemical composition of the RABBIT my guess is that this is caused by the high ACIDITY level of the Madeira, not due to its alcohol content. I assume that you also left the bottle standing up not storing it horizontal, as it is supposed to be, especially when already opened…

I always have a Broadbent 10 year Malmsey on my counter and I just re-use the cork stopper that came in the neck. If I had to find something else, maybe I’d find one of those bottles of rose that comes with the re-useable glass stopper, but that usually has a rubber/plastic gasket. I’ve got some metal and/or glass decorative stoppers, so I’d bet you could find something like that

I keep a couple old corks on hand for closing any bottle that may need recorking. They generally need to be trained so that they form a little bit of a taper that allows them to go back into a bottle. If left on their own once outside the original bottle they tend to expand and can be difficult to get into another bottle. The taper is formed by putting it partially back into a bottle and letting it rest like that for at least a couple days. Once shaped like that they tend to hold pretty well. Cheap and effective.

Just to make it clear: Madeira is always meant to be stored and kept standing upright, but especially when already opened.

Yes it was upright the whole time.

I drink a lot of Madeira, and I do have an RWC sitting in the cabinet with a stopper in it. I’ll have to check it when I get home. Frankly, I’m having a hard time believing just the fumes from the wine would damage the stopper. I would be more likely to believe that the material the stopper is made out of outgassed and it’s degrading on its own.

1 Like

Use t-corks. Amazon sells many sizes and compositions. Measure the diameter of the bottle opening for proper sizing.

BTW: I exclusively use natural corks from already emptied Port bottles, never had a problem; f**k plastics, re-using old cork also supPORTs sustainability.

1 Like

Here’s a photo of my stopper, which has been in a bottle of RWC Boston Bual for at least 18 months, standing in a cabinet. The bottom portion is definitely discolored, but the material itself is 100% with no degradation at all.

I don’t use reused corks because I don’t want to take a chance on introducing TCA where there had been none before.

Ahhh interesting. Similar discoloration to me, though without the structural degradation of the rubber. I don’t know though, even if the rubber seems intact, the discoloration indicates that some sort of chemical change is happening. Are chemicals being released? Is anything going into the wine? Whatever is happening, I’m going to look for another closure.

I collect old hard rubber pens, and they also had rubber ink sacs in them. It’s very prevalent for this material to outgas as the material is affected by the requirement. My guess with these stoppers is that there is an effect from the fumes of the wine causing the stopper material to outgas.

Is there an effect on the wine? Could be, as that gas is contained within the bottle. I’ll try a glass tonight to see if there’s any change to the wine, and then report back.

Is this a unique phenomenon with Madeira? My guess is no, but Madeira is the only wine where these stoppers get used for more than a day or two. I suspect that long-term exposure to the alcohol environment, while not touching the wine, is affecting the material of the stopper. My conclusion is that these stoppers are fine for a day or two, but not for months/years.

If you buy frasqueras from D’Oliveiras or Barbeito, they usually provide a tee top stopper. I just reuse these.

Yet more dangers of leaving wine around undrunk.


Lot of handwaving here lol.

I’d try this experiment: pour a small amount of the wine in a glass, and drop the offending stopper in. See if it starts to dissolve/disfigure after a few days.

Alan, you are right. I like to avoid handwaving. I want to figure this out. As I see it, the potential culprits for degrading the stopper are alcohol, acid, water (unlikely), a combination of these, or something else entirely. To test these, I took a stopper, cut it into pieces and set up the following conditions:
1- Control- stopper piece sitting in an empty bowl
2- Water- stopper piece submerged in tap water
3- Moderate alcohol/Moderate acid- stopper piece submerged in white wine 11.5%ABV (don’t have pH unfortunately)
4- High acidity- stopper piece submerged in white vinegar
5- High alcohol- stopper piece submerged in 40% ABV brandy (didn’t have vodka on hand)

I think this is a decent study design, though I see potential limitations:

  • Some other component could be degrading the stopper- I’m not sure what this might be or how to test for it. So this will have to go untested for now.
  • Different color stoppers could have different susceptibilities to degradation- Unfortunately I threw out all my Rabbit stoppers and I only have this maroon colored one left. I’m not going to buy more. Maroon will have to do.
  • The cut surface of the stopper might have different susceptibility to degradation than an intact stopper- Oh well, I only have one stopper left. Cut up pieces will have to do.
  • There is something specific to Madeira that causes degradation that is not included in my experiment- In an ideal world, I would have a Madeira condition. However, the only Madeira I have on hand is an old, expensive, rare Madeira that I’m not willing to waste on this ridiculousness. Even an ounce of it.
  • Gas vs liquid phase might result different degradation- the stopper that prompted this post was exposed to vapor from Madeira. This experiment is being done by submerging in liquid. This could be fixed by filling a bottle with each of the respective liquids, stoppering them, and tracking them over time. That requires a lot of stoppers, a lot of bottles, and a lot of space. Maybe in the future, but this experiment is a good first step.

The finally limitation is that I’m only able to run this experiment for 2.5 mos. The stopper that prompted my initial post was in place for well over a year. But, I’m moving and there is no way that I’m preserving this experiment and moving it with me. If it is inconclusive at the time of my move, I might just recreate it and start it from scratch in my new location.

Here is a photo of the whole setup. The wine at the end is a glass of 2016 Miani Saurint Sauvignon Blanc. It has nothing to do with the experiment other than it was what I was enjoying when I set this up. Amazing wine.


Guilty as charged.

Lol, just happy to have someone else shouldering the science mantel around here. Your experiment looks great, let us know what you find!