Issue link: http://winesandvines.uberflip.com/i/804714
62 WINES&VINES April 2017 WINEMAKING the permeability of the ceramic material to the liquid in the tank. The company's literature describes a process of evaporative cooling that cools the surface of the tank, which then transmits that energy to the wine in the tank. As wine cools, it becomes more dense and slowly sinks to the bottom of the tank. Through the process of the cooled wine sinking to the bottom of the tank, the wine at the center of the tank, which is slightly warmer, rises to the top. The egg- shape, having no sharp angles on its inside surface, translates the upward movement of the wine to a cascade down the outer shell, where the wine is cooled by the shell surface. With this movement, caused by the temperature differ- ential, the two areas of the tank mix continually and gently. This dynamic is not necessarily happening in standard concrete tanks, since the walls of those tanks, while porous, are much too thick to cause the slight tempera- ture effects of the thinner, ceramic- walled vessels. However, one could make the argument that the So- noma Cast Stone glycol system might impart that same effect. The Vital Vessels tanks are a maximum of 675 liters and, since they are made of ceramic materi- als, they are quite different from concrete tanks. For example, the wall thickness is measured in mil- limeters (the walls are 9 to 12 mm thick), not multiple inches of ma- terial. Since the tanks are ceramic, they could be subject to cracking due to shock. To guard against that possibility, each tank is fitted with stands with insulating pad- ding for protection; there are polymer pads between the tank and the stand, and the stand and the floor. Vital Vessels makes smaller tanks (down to 43 liters) that are used for water and other beverages. The company says that these tanks are fired in one of the largest ceramic kilns anywhere and take 42 hours to fire. There are other small tanks being produced from concrete that are not egg-shaped. Vino Vessel in Paso Robles, Calif., has created a line of concrete tanks and a con- crete barrel. In addition to its egg- shaped tanks, Sonoma Cast Stone has just designed a four-barrel tank that is squat and chest-like; it can be stacked two high. The benefits (and problems) of concrete tanks Many wineries are now using the concrete egg-shaped tanks. When InnerstaveBarrelAd12.27.16Fin.pdf 1 12/27/16 10:31 AM Flextank's egg-shaped Apollo unit is hoisted with a sling in order to dump fermented grapes into a basket press at Lobo Loco Wines.