Issue link: http://winesandvines.uberflip.com/i/66144
CL OSURE S Understanding Technical Corks How high-quality, inexpensive one-plus-ones and agglomerates evolved By Jamie Goode Highlights It is imperative that agglomerates and micro- that many people in the trade aren't even familiar with the term "technical cork." It refers to a natural cork-based closure made by combining discs or granules of natural cork to produce an inexpensive closure solution. They now represent around half the business of Amorim, which is by some distance the world's largest cork company. This article will take a closer look at this category of closures and assess their merits compared with other closure solutions. T Champagne corks The story begins in Champagne, France, birthplace of the original technical corks. Although people commonly think of sparkling wine corks as being mushroom shaped because of the way they appear when removed from the bottle, before they're inserted they consist of a cylinder roughly twice the diameter of the bottle bore, with a distinctive deep chamfer (the technical expression for the smoothing off of the rim) at the top. The problem with producing such a large-diameter cylinder entirely from natural cork is that most cork bark is not thick enough to make them. As a result, Champagne corks are made largely of agglomerate cork—the only natural cork elements are the two or three discs that are in contact with the wine. 32 Wines & Vines AUGUsT 201 1 echnical corks are proving to be increasingly important wine bottle closures, but compared with synthetics, screwcaps and natural cork, they get relatively little coverage, to the point • Wineries have been adopting natural cork-based, agglomerated closures because they offer increasingly better quality for a low price. • The article details various types of technical corks and discusses recent breakthroughs in TCA control. • Micro-agglomerates are the most upscale option, offering cork-like ap- pearance and prices competitive with synthetic closures. Normally, natural cork is punched tangentially to the face of the bark, which has first been cut into strips of suitable width. But with thinner pieces of bark, it is possible to cut sheets of high-quality cork a few millimeters thick in a plane paral- lel to the flattened cork bark planks, and then punch discs from these. By gluing these discs onto the end of an agglomerate cork component, Champagne corks can be made affordably, with just the high-quality cork in contact with the wine. The agglomerate component of Cham- pagne corks is made by bonding together small cork fragments—typically 5mm to 8mm in diameter—using food-grade glue that includes polyurethane. The production process is based on extrusion, producing long tubes or rods of agglom- erate that are then cut to the appropri- ate length. Agglomerates are extremely cheap because they are made from pieces of bark that otherwise would not be suitable for cork production as well as the material that is left after corks have been punched out of planks. In its various forms, agglomerated cork is the basis of most technical corks on the market today. agglomerates are made from cork that has been The Twin Top and its competitors The most significant technical cork is the Twin Top developed by Amorim (whose products are sold in the United States by two wholly owned subsidiaries, Amorim Cork America and Portocork) in the mid- 1990s. It's a closure that adapts the tech- nology used for Champagne cork produc- tion. "Champagne corks are not only an important product for cork companies," says Carlos de Jesus of Amorim, "but also led to the development of the Twin Top." Cork companies realized that Cham- pagne corks were performing well, de Jesus says, with low levels of taint and consistent physical performance. "We asked ourselves how we could transfer this technology to still wine closures and get good results." The Twin Top has an agglomerate core sandwiched between two discs of good- quality natural cork. The advantage of having natural cork at both ends of the closure is dual: first, no orientation ma- chine is needed before the cork is applied on the bottling line, and second, the consumer sees nice-looking natural cork (not agglomerate) when they remove the capsule. Launched just 15 years ago, the Twin Top is now the best-selling techni- cal stopper in the world, with sales of 650 million units per year. They are usu- ally employed for large-volume, price- sensitive wines for which the cost of good, natural cork would be prohibitive. Other cork companies now produce their own versions of the Twin Top, which is also known generically as the "one-plus-one" (although, technically, this