Mushroom-shaped Corks made from agglomerated cork in any size
Agglomerated Mushroom Corks
Mushroom Corks, also known as Champagne corks, are made from three pieces of cork sandwiched together. The mushroom shaped head protrudes from the top of the bottle, allowing the wine drinker to get a good grip on it when easing it out.
Pressure beverages such as champagnes, ciders, sparkling wines, and some beers require a seal which prevents the escape of gases while at the same time preserving the correct gas pressure within the bottles. Mushroom corks produced from natural cork are the perfect stoppers to achieve this critical sealing capability. Each cork is usually produced from several different types of natural corks. The main body of the cork is made of agglomerated cork grains bonded together by FDA approved binders. Laminated to this "body" are two or three natural cork discs which have maximum expansion characteristics. The usual diameter of mushroom corks is about 31mm and is compressed down to 18mm to fit into the bottle neck it is to seal. Once inserted the corks' tendency is to continue to expand. This expansion causes the cork to maintain a constant pressure against the glass bottle neck, preventing the gas from escaping.
Initially these mushroom corks are "straight" before they are put into the bottle. The "mushroom" shape is a result of the inserted portion of the cork being compressed in the bottle. Once pulled from the bottle the lower part of that portion of the stopper (the natural cork discs) continues to expand shaping itself into a "mushroom".