We receive a lot of questions about how cork stoppers should be stored once they have been received by clients. The most important thing is that once you have received your cork stoppers from your supplier, you should use them to bottle your wine or whatever within around 6 months. After this time the surface treatment (generally silicone or paraffin) that has been applied to the corks to lubricate them and allow them to slide into the bottle more easily will start to dry out and they will become more difficult to insert.
It goes without saying that corks should be stored in a dry and cool location to minimize the risk of mould or fungus affecting them – some bottlers like to have their corks supplied in sealed bags with an inert gas applied, but this is not strictly necessary as long as the corks are stored in appropriate conditions.
The 6 month rule for storing treated corks applies to all cork types: natural corks, agglomerated corks, 1+1 corks etc. If you are buying corks from a national distributor, rather than direct from Portugal then you need to be 100% sure about how long they have been sitting in a warehouse before they are delivered to you. Best of all of course, you should buy your corks direct from Portugal, straight from a cork supplier, where you can have corks produced to your exact specification and be completely confident that they are freshly treated.
Here at CorkLink of course we love natural cork – what is there not to like? It comes from sustainable forests where the trees are not cut down to harvest the cork bark, the product is beautiful in the way that only natural wood can be, it is the only way to allow wine to age in the bottle and it makes a fantastic sound when you pull it out!
Here is everything you need to know about why you should a natural cork supplier rather than going for a plain old screw cap:
Do yourself a favour and choose natural cork!
We supply natural cork balls in sizes of 8, 10, 16, 18, 20 and 25mm (and agglomerated cork balls in these sizes and larger). Natural cork balls are in fact very difficult to produce in high quality, as they need to be worked delicately and also need to be made from good quality natural cork in order to not have too many imperfections.
We are able to produce high quality natural cork balls in high enough quality to produce for example necklaces and other jewelry as well as a range of craft products, whistles and so on. We are also able to add a hole in the balls if required. We are able to supply from a minimum order of 100 upwards.
We have a new catalogue of cork leather bags and other cork leather products – you can download it here
You can download the cork leather bag price list here. Please enquire for wholesale prices.
There are not many industries that Portugal can claim to be the world leader in, but cork is one of them. In fact around 70% of the world’s cork is exported out of Portugal and for quality natural cork stoppers, the figure is over 95%. So if you are buying cork from within your own country, the chances are that it originally came from Portugal.
Southern Portugal has abundant cork oak forests, with 5.3 million acres in total (around 8% of the total land area of Portugal), giving an annual harvest of around 310,000 tonnes of cork. A number of national markets are dominated by local distributors who are typically buying their cork from Portugal, storing it and selling from stock. Here at CorkLink, we supply the end customers (be it the bottler, builder, furniture maker or whoever!) direct. This allows our customers to have more input into exactly what they buy, rather than having to buy stock items.
So for example when we have a new client interested in buying cork stoppers, particularly for bar-top corks, we generally ask for a sample of several of their bottles and we check the internal profile of the neck of the bottle, checking to see both consistency between bottles and also how the bore of the bottle changes along the length of the cork. This enables us to give a recommended cork size to within 0.2mm for the diameter of the cork. We can then also look at some different surface treatments that the corks may have, as well as branding on the corks and again in the case of bar-tops a huge variety of capsules (wood, metal, plastic, with a series of different surface treatments available).
Buying direct from Portugal will also help to keep your costs down as you are buying direct from source and another key advantage is that in the case of natural corks, you can be sure that they will have been sorted and graded correctly, whereas many distributors mix up the different grades of corks in order to pass off lower quality corks as premium.
So if you are looking for a cork supplier, then why not buy direct from Portugal. And if you are going to buy cork from Portugal, then you just need to speak to CorkLink!
It will come as no surprise that here are CorkLink we are passionate defenders of using cork to seal wine bottles – after that is a big part of how we make our living! I would like to have a look at some of the arguments that need to be considered when choosing between screw caps or corks.
Natural cork is used for around 70% of the 18bn wine bottles produced, with screw caps taking 11% and plastic corks 20%, whereas 10 years ago, cork was used for around 95% of wine bottles. The main reason for the increasing usage of screw caps is that they are cheap and that they do not suffer from cork taint (the nasty flavour that poorly produced corks can give to wine, via the chemical TCA). The truth is that well produced natural corks will have TCA problems with less than 0.2% of corks, following several years of heavy investment to resolve this problem, by improving the conditions that cork is weathered in and the various treatments given to the cork to get rid of anything nasty. It is fair to say that natural cork (when produced by a cork producer that has made the relevant investments) no longer presents a major threat to wine.
Screw caps on the other hand represent their own problems – by not allowing any oxygen at all to reach the wine, volatile compounds such as hydrogen sulphide and mercaptans which form naturally and sulfur dioxide and sulfites which are added to the wine as a preservative, can get trapped inside the bottle and worsen. This is the rotten-egg or boiled cabbage smell that you can get when you open a screw cap bottle of wine.
There is pretty much no dispute that for a wine that is going to age in the bottle, cork is the only serious option, as it allows just enough oxygen in to enable the ageing process to take place. But for wines that are not going to age further, several winemakers are now rejecting screw caps because of volatile compounds odour problem. So for example Adam Mason at South Africa’s Klein Constantia gave up on screw caps after 4 years, as did Christian Canute of Barossa’s Rusden Wines after 5 years of screw caps.
The technical arguments will continue about what kind of closure is best suited to a certain kind of wine. There is no doubt however that natural cork is still a signifier of quality in most consumers’ eyes. For the same reason that when you buy a smart dress in a fancy shop they give you a nice bag to stuff it in rather than a supermarket-style carrier bag, it makes sense for winemakers to present their wine in the best possible light. Wine is a magical product and deserves to be presented in the best possible light and cork still remains an important part of the magic!
We have a stock of 700 used wine casks/barrels 500 litres each in heights of 1.50m and 1.17m available for sale pictured below. Price is €85 each as is. Their condition is not perfect, although we can recondition for them for you if required. They were used for making Portuguese red wine.
Please contact Charles at email@example.com if you are interested.
So should you choose agglomerated or natural corks for your stoppers? Assuming that you are not going to use a synthetic option (screw tops or worse still a plastic cork imitation), what are the different characteristics of agglomerated and natural corks?
Within the agglomerated cork bracket, you can opt for micro-agglomerated (with 0.5 to 2.0mm granule size) which have the advantage that they are stronger and harder wearing that standard agglomerated corks and then you can choose between extruded and moulded agglomerated corks. Extruded agglomerated corks are the cheapest cork option and the reason is because they are not very strong, so more likely to break when uncorking a bottle and giving a less reliable seal to the bottle. Moulded corks (which are always micro-agglomerated) are a much higher quality option and are becoming increasingly common in the industry now, because they are much stronger and their reliability/consistency is much better than extruded corks, but they are twice the price of extruded corks.
Increasingly moulded agglomerated corks are taking market share from natural corks and the simple reason is price. Natural corks are extremely complex to produce given the fact that they have to be produced from uneven cork bark and then selected and divided by quality (and then selected and divided again after treatment) and are less easy to sterilize than agglomerated corks. This makes good quality natural corks expensive and there is no point pretending otherwise, but is the extra money worth it?
There are three great advantages to natural cork:
- its natural porosity will allow a wine to age in a bottle that an agglomerated cork would not
- agglomerated corks contain synthetic binding agents, which although food-safe are not ideal to be in contact with the delicate flavours that many drinks have
- natural cork looks beautiful and organic, whereas agglomerated cork is uniform and looks semi-synthetic
So natural cork is the best closure for high quality wines and spirits and confers a feel of quality and a nature to drinks that are bottled with it. You can look at natural cork as steak compared to agglomerated cork as burger meat – they both have their place in the food market, but when choosing between natural and agglomerated you need to decide if you are selling fast food or fine dining…….
The system of classifying natural wine corks into different quality categories is to say the least a complex one. The key thing to understand is that there is no cross industry standard applied to corks coming out of Portugal (where the vast majority of natural wine corks are produced) and more complicated still, broad quality standards vary considerably from country to country. So a natural cork considered generally to be of high standard in a south American country, might be generally considered of indifferent quality in the US market. These differences are largely a result of unscrupulous distributors peddling corks as being of a higher quality than they should be and mixing batches of lower quality corks into higher quality ones in order to fool winemakers. The only real solution to all this nonsense is to try and avoid national distributors and buy direct from an honest supplier in Portugal!
Anyway, here you can see a photo of 4 corks that we selected from 4 different quality samples (from left to right – Second – First – Super – Extra). In terms of the mechanical integrity of the corks, they will all be pretty much the same and in terms of the manufacturing process, they have all been treated in exactly the same way. The real difference is in the appearance of the corks, so the “Extra” quality cork will have only minor imperfections in the surface, whereas the “Second” quality may have some quite large holes.
In very broad terms, you might pay 240 euros per thousand for Extra quality 45x24mm corks, but 120 euros per thousand for Second quality (as a reference point, agglomerated corks you might only pay 30 euros per thousand for). Agglomerated and micro-agglomerated corks have there place for providing a low cost option for wine corks, but they do not confer the badge of quality for wine that natural corks do – here you can see an agglomerated, micro-agglomerated and natural cork side by side.
Because cork is a natural product that can only be harvested from one kind of oak tree, there is a limited supply. It is also quite expensive to harvest from the trees, as the bark has to be removed by hand. This means that cork is not a cheap raw material! It has unique properties and has a certain beauty to it, particularly in its more natural forms, but you have to pay good money for it and there is no point as a producer of cork products pretending otherwise and trying to compete directly with cheaper, lower quality synthetic alternatives.
The relatively high price of cork means that not a single speck of cork is wasted however. So cork that comes off the trees that is not of suitable quality to make natural wine corks is either used to make expanded cork (if it is resinous) or granulated, so everything that comes off the tree can be used. Then the off-cuts that are produced when the natural wine corks producers punch them out is also granulated. The dust that is created when the corks are sanded down to size is collected and used to power the furnaces that heat the water used to treat the cork. Larger waste scraps of cork that are produced are added to granules and compacted to make decorative boards for cork flooring. And now in some countries even used corks are collected to be granulated and used again.
The key to the industry is natural wine corks however, because these are the most valuable part of the industry (a single ‘flor’ quality wine cork can cost over one euro!). The value that comes from these wine corks, means that the rest of the cork used for agglomeration, flooring, moulding etc can be sold at a lower price. The natural wine cork sector is competing with synthetic corks and screw-tops as well as being undermined by the growing popularity of micro-agglomerated and technical wine corks; without the relatively high value sales that come from natural wine corks however, there will not be sufficient value left in the industry to pay for the expensive harvesting of cork. So it is vitally important that natural wine corks get all the support possible, because the entire cork industry depends on them. Natural cork is a wonderful product and in a world where “natural” is increasingly prized over “synthetic”, we have to hope that wine producers and drinkers will continue to value the amazing properties and beauty of natural cork and not always look for cheaper alternatives, because an entire industry depends on it.
Or put another way – this is why you should use natural cork!