Cork Dept: Cork taint with rum?

[Capn Jimbo]

No, this isn't an article about rating rums....


Unlike the faux reviewers who actually rate a rum by it's bottle, label and/or closure, today we're going to discuss a subject that I've never seen on a rum site: corking. And I don't mean the lovely resonant "pop" we all love. What do I mean?

This refers to the great debate between the producers of classic and authentic cork closures vs those who make and promote synthetic "corks". We'll ignore the screw top contingent for now. The "natural" folks promote what we already tend to value - a classic, natural and classy seal - the natural cork. And as we all know the downside are the many low grade corks that allow excessive breathing, loss of alcohol and that often dry out and crumble.

The "synthetic" crowd produces an artificial cork that looks nearly as good, sounds just as good, and seals reliably. The downside? Some feel that like plastic bottles, exposing a synthetic to alcohol for a long period of time might not be safe.


But here's a first, for us anyway...

Those of you who drink wine are aware of the common practice of smelling the cork before accepting the bottle to see if the wine was "corked" - referring to the fungal, moldy newspaper, basement aroma, which also implies a similar taste. This is a quite real phenomena called "cork taint" whose chemistry is well known. It has been shown that this fungus amounts to a combination of airborne fungi combining with pesticides and/or the chemicals used to bleach the cork. Although the industry states this affects only 1% of wine bottles, most wine drinkers believe that "corking" is more common.

We too have rejected corked wines, but never a "corked rum". Until now.


Entre La Mauny "AOC Rhum Agricole Martinique"

This cane juice style rum boldly proclaims "AGED" on the front label, but hides "for at least 12 months" on the back. Sue Sea had a particular connection to this rum through a good friend and was very anxious to do a tasting. She simply adores cane juice rums.

We set up our usual tasting, poured two drams and had at it, beginning as always with nosing and then finally getting to the palate. This time Sue Sea looked puzzled and spent an inordinate amount of time nosing, so much so that I was caused to ask "Are you having trouble?". "Just a minute," she replied, "I need to taste this now". And she did. After an equally long tasting she said "Give me the cork." Puzzled, I did so and she nosed it and exclaimed:

"That's it! This rum is tainted"

I had trouble believing this, so I too checked the cork and revisted the rum. At first I wanted to believe this was simply the nature of this AOC branded rum by regulation. But the evidence was clear - there was absolutely the unpleasant classic "cork taint" moldy aroma, also noted in the taste. We experimented and left two drams out to air for perhaps a half hour which improved but did not eliminate the effect.

It is worth noting that according to the Wiki, modern studies show that aging barrels and storage conditions may also be responsible. For example used sherry barrels are emptied of any residual sherry, then nosed to determine if the barrel has "gone bad". If so, it is rejected or disassembled, shaved, reassembled and charred.

Question: have you ever had a "corked" rum?

[Capn Jimbo]

...bump

Guyz, forgive me for bumping this but I fear some may have missed this one, and may have experienced "cork taint" with a rum. Thanks for the intrusion, I'm really curious about this one...

[jankdc]

Thankfully, no I have not experienced it. I'd hate to plop 30 down on a rum that I couldn't drink.

[da'rum]

Me neither mate, I've never had a corked rum.

[RT]

I have experienced two occurrences of defective corks in rum. The first was a bottle of Vizcaya VXOP several years ago, and the second was a Botran Solera Reserva I bought just 2 months ago in Puerto Rico. Neither bottle was exactly "cork taint" like you might find in wine, but rather a low density, dry, crumbly cork that fell apart upon initial opening of the bottle. I did not perceive any musty flavors, just a relatively flat, flavorless (oxidized?) rum that could not be enjoyed neat. Both were relegated to my rum&coke(tm) shelf.

[sleepy]

Just a couple of thoughts as to why cork taint is improbable in most spirits:
1) For preservation of the air seal in wine sealed with corks, the bottles are stored horizontally, providing a moist, if (ideally) anaerobic growth medium - dry cork deterioration as noted above is probably more likely in vertically stored spirits; and 2) I'm reasonably certain that the upper limit for bacterial/fungal (and yeast) growth is well less than 20% EtOH - I'd guess that the vapor between the surface of a vertically stored bottle of rum and the bottom of the cork would exceed this level.

[Capn Jimbo]

Let's be careful in our assumptions...


Sleepy, it appears the assumptions on which you hypothesize that cork taint is improbable in rum, et al, are these...

1. That the process is anaerobic.
2. That rum bottles are stored upright.
3. That the cork is not already infected at bottling
4. That the percentange of alcohol vapor is equal to the percentage alcohol in the liquid, ie the rum.

The only factor that stands alone (pun intended) is #2, that the bottles are stored upright. The others are confounding assumptions. Just a quick run through the Wiki provided at least one instance of distillery fungi that thrive on alcohol:

Baudoinia compniacensis is an ascomycete fungus that has been observed on a wide range of substrates in the vicinity of distilleries, spirits maturation facilities, and bakeries. The fungus is a habitat coloniser with a preference for airborne alcohol.

Other quick sources indicate inhibiting (but not eliminating) effects of water, ethanaol, glycerol, sorbitol, et al. The problem here is that there are so many different types of fungi with widely variable effects in the presence of ethanol.

Here's what we do know:

1. A certain percentage of cork is already tainted before bottling.

2. Cork taint is a very peculiar and recognizeable aroma.

If this cork was tainted, it is possible that it was already tainted before bottling and that the tainted components transferred to the rum. It was certainly in the cork. If it was not tainted, then there is another product of fermentation, distilation and/or aging that either mimics taint, or is yet another source of taint. For example ex-sherry barrels are known to "go bad", which is determined by aroma. If the barrel is deemed "bad", it is either disassembled, shaved to new wood and recharred or toasted, or simply rejected outright. La Mauny is aged in French oak.


Bottom Line

For now we lack the information to be definitive one way or the other, so we are left with making a subjective judgement based on our individual past nosing experiences.

[sleepy]

Just a quick correction - I think that the process is aerobic and can progress due to a poor bottle-cork seal or a dry, or otherwise compromised cork allowing air-flow, if limited, into the bottle. My microbiology was 40+ years ago, but I'm pretty sure that there are few anaerobic fungi, mostly limited to gut flora. Again, a superficial search seems to indicate that the TCA/TBA producing fungi are aerobic.

Although I have encountered a few bottles of corked wine, I've not had one of any spirit. I'm thinking that if it does occur, it must come from an already contaminated cork, with, probably, the the TCA/TBA contamination already present. Given the miniscule concentrations necessary to introduce "tainted" flavor, it does seem possible.

I wonder if fools (it seems that idiots would be inappropriate in this forum ) buying 50-100 year old armagnac have ever found that their 5-figure investment was trashed by corking?

An interesting side note that I encountered in brief research was the statement that spirits, especially older ones, should never be stored on their sides due to risk that the high alcohol concentration in spirits might speed the deterioration of the cork - leading to a different form of "corking".

[jankdc]

An interesting side note that I encountered in brief research was the statement that spirits, especially older ones, should never be stored on their sides due to risk that the high alcohol concentration in spirits might speed the deterioration of the cork - leading to a different form of "corking".

So what's the best way to store long term. I assume that plastic/screw top doesn't matter, but corked rum? keep upright, but periodically tilt so that the cork gets wet?

[sleepy]

As I followed the discussion (regarding a very old bottle of rye) the consensus seemed to be simply store upright. Remember that most spirits with cork stoppers also have some form external seal - wax, heat-shrink plastic,... As long as that outer seal is intact, I doubt that the cork is going to change in its constant environment. Once the outer seal is broken, you'll just have to drink it

[The Black Tot]

I opened my bottle of Myer's Legend about two months ago and had a mixed reaction.

I could tell that the rum was excellent, and had rare complexity and quality...

...but it also had this very ugly bite at the end of the sip, that didn't taste as though it was intended to be there at all. Since that was the only bottle I've tried, I couldn't say for sure if I had a bad bottle.

I did wonder if this could be cork taint. As with many of my old rums, the cork shattered upon removal. At the time, I did not think to sniff the cork directly for clues. I decanted the bottle into smaller flasks and will revisit it later.

There was more where I bought it on the shelf, but I would want a second opinion before going after more from the same batch on whether or not this is representative of the intended Legend profile.

[Capn Jimbo]

What a shame!


Even before the Big Three takeover Legend was a bit hard - but not impossible - to find. Now it's simple g-o-n-e. Mine has become a very special occasion dram. What a shame this happened to yours. Do let us know whassup later...

[JaRiMi]

I've met tainted cork in whisky, not rum.

We had a Glengoyne tasting one time for some 30 people, and the 21 year old was opened - voila, it was - spoiled! Much to our disappointment, it was "corked" - i.e. it tasted and smelled like a msty old cellar, NOT like the 21yo Glengoyne normally does (verified this later).

It can happen, even if it is rare.

[Nekkandor]

I did. Two bottles of the bottling "Samaroli Barbados 1996 - 2011". I will never forget the ugly nose and taste of these rums. First I thought only one bottle was spoiled but then I openend the second one and my day was ruined.

This was nearly 2 years ago. You could clearly notice it on the palate and in the finish. A disgusting experience.

[The Black Tot]

Yikes, with Samarolis!!!

I only just recently learned what those are. That would definitely be an ouch moment!