You spend great effort and time making sure that your wine turns out perfectly, and in the haste to get your wine bottled the importance of good corking is often overlooked. Shortcuts can lead to disastrous results.
Cork is a natural product made from the bark of the Cork oak, indigenous to Portugal and Southern Spain. Sheets of the bark are steamed flat, pressed, and the corks are drilled out with hollow drills. Like, other plant products, cork bark tends to vary in thickness, hardness and texture, and as a result there are corks of several different lengths and degrees of quality.
It is a fact that the longer the cork, the longer it is likely to remain an intact and viable stopper, and the more resistant it will be to allowing oxidation of the wine inside. This is important if you are planning extended ageing of their wines.
Acceptable corks have certain attributes which are easily identified. All good wine corks have smooth, straight sides and are not too hard that compression into the bottle is difficult or impossible. As well, there should be no elongated cracks or fissures running through the cork.
The styles of cork available have cost and quality implications, with the rule being the higher the quality, the higher the price. That is, natural or 5 year corks offer a higher standard than agglomerated “composition” corks.
Despite the fact that corks are typically disinfected and sealed in large plastic bags, proper storage and preparation of the corks prior to corking is highly recommended. Corks should be ideally stored in a ventilated, odour free environment, at temperatures between 15 and 20C in a humidity of 50-70%. If you want more information on this ask us about designing your own simple cork humidor.
Natural corks should be soaked in a mild sulphite solution and water to protect against dust, dirt, yeasts or mould they may contain. But, if left to soak too long, excess moisture and soluble materials will be pressed out into the wine. Never, soak corks in warm or hot water. We recommend soaking them for 20 minutes prior to insertion.
Synthetic corks are a different story, but we will leave that discussion for another day.