Thursday, April 20, 2017

Cracked Wine Cork

Cracked Wine Cork

Cracked Wine Cork on a 2013 vintage presenting fissures/cracks and mold  - LeDomduVin ©

Recently, I came across some bottles of 2013 vintage, coming directly from Bordeaux, presenting fissures/cracks and mold under the capsule, while no sign of mold or humidity could be found on the bottles or even the cases. As it is not normal, a few questions came to mind: 

1. Why the fissures or cracks on the cork? 

It is a young vintage (2013), recently bottled (2015), and therefore the cork should be in excellent conditions, so why the fissures/cracks? 

A. Bad Quality Cork

Nowadays, finding bad quality cork is quite rare as quality controls at the factories and sampling by the buyers prior final selection are more rigorous and consistent than before. Although, it can still happen and surprisingly more often than we think. 

One of the main reasons is in my opinion due to supply and demand.

Out of the 195 recognized independent countries in the world, more than 72 countries are producing their own wines as of 2014 (see the map below for reference and related wikipedia article), against less than 50 only about 30 years ago. Some people even refer to about 120 wine producing countries at present, but those at the bottom of the list are marginals, only the top 40 are major players in terms of production.

Interestingly enough, you may realize that the wikipedia article and the map below do not show some countries that also produce wine (some for decades too) like: India, South Korea, Thailand, Vietnam, and a few more.  

World Wine Producing Countries Map as of 2013 - Data from FAOUN 
Although, a trend for plastic corks and screw capsules developed in the late 90s and 2000s after a major crisis of tainted cork (*), the 2010s saw the comeback of real cork due to its natural and environment friendly benefits.

"The improvement in the quality of cork, the problems associated with artificial closures and the unwavering consumer preference for cork stoppers, are increasingly the key decision-making factors for wineries to choose cork stoppers and not the so-called alternative products. In the market benchmark of the USA, a study carried out by A.C. Nielsen between 2010 and 2012 confirmed an increase of 26% in sales and 23% in revenue from wines sealed with cork stoppers - against a decline of 12% and 7% respectively, for artificial closures. According to the study, 61% of the 100 top premium wine brands use cork stoppers. The study focused on the main brands priced above 6 dollars (4 euros), which shows that the choice of cork is increasingly broader and competitive, against artificial closures." Extracted from the famous cork producer "Amorim" website (read more here)

(*) Back in the late 80s and early to mid 90s, many renown wineries in Bordeaux (and other regions of France and the rest of the world) were found with a major problem of tainted cork (or cork taint, often referred to as TCA, resulting in "corked" wine) occurring due to either chlorine based chemicals used to clean/bleach/disinfect the cork, thus imparting the cork quality, and/or poor cellar hygiene.

TCA stands for 2,4,6-trichloroanisole, a powerful chemical compound, which cause musty aromas and flavors in wines. The compound forms through the interaction of plant phenols, chlorine and mold. It most frequently occurs in natural corks (TCA can even form on tree bark), transferring it to the wine in the bottle. But also can originate
  • At the cork factories, where chlorine based bleaching/disinfecting products are (or were especially in the 80s and 90s) used to treat the cork as part of its production. 
  • In wineries, where damp surfaces and chlorine-based cleaning products are (or were) commonplaces. Phenols can be found in barrels, wooden pallets, wood beams and cardboard. If not rapidly detected TCA can spread and eventually taint the wines via contaminated corks. 
However, while cork quality has improved drastically over the last 15 years, as wine producing countries rise, so does the supply and thus the demand, generating a major problem in the production and supply of cork, and consequently its quality. The main factor being the increase of cork harvests and diminution of time between the harvests.

Cork Oak trees (Quercus Suber) found predominantly in Portugal and Spain, and the northwestern part of Africa (Morocco, Algeria and Tunisia), must at least be 25 years of age (or 60cm minimum in diameter) for the bark to be harvested the first time, The first harvest not producing quality cork, the cork is usually sold for other uses than wine cork (flooring, shoes, insulation, fire retardant materials, etc,..). Subsequent harvests are now occurring every 8-9 years, compared to the needed 12-13 years to obtain optimal quality. Consequently, nowadays cork are somewhat less resistant  

B. Bad Storage Conditions

The cork may have dried out due to bad storage conditions, right after bottling, while stored at the Chateau (property) or at a Negociant's warehouse, or any other facilities that may not necessarily be well adapted or designed to keep wines in an ideal environment and climate. (Personally, I have seen and experienced many wines being very badly stored in my 25 years career as a Sommelier-Wine Buyer, sometimes even at prestigious Chateaux and renown Negociants.. but this could be the subject of another post). 

Bad storage conditions usually involves:

Bad Storage Conditions
Effects on cork (label and wine)
Lack of Humidity

Ideal Humidity level being between 65 and 75%,
below 60% the cork will easily dry out
above 80% the label will get damaged and mold could form on label and cork under the capsule

Too much ventilation

A cellar should be well ventilated,
but not to the point of drying out the air

Non LED lighting

Heat usually emanates from non LED lights
and dry out the air too if left on too long

High Temperatures

Ideal level being 11-13°C up to 15°C maximum,
anything above 16°C being too warm,
and anything above 21°C for more than just a few hours could rapidly damage the wine

Temperatures and Humidity fluctuations

Can have a direct effect on the cork
(also label and most certainly the wine itself)


- Or if not during storage prior been shipped, the cork could have dried out during transportation, for example if the container was not reefer and the wine was shipped during hot weather, Non refrigerated container can get really hot inside during the journey to the final destination, which could last for several weeks (e.g. as per, shipping time between "Le Havre, France" to "Hong Kong" takes about a month). 

Screenshot of Le Havre, France to Hong Kong

Work in progress...... 


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