Issue link: http://read.dmtmag.com/i/467731
w w w. v w m m e d i a . c o m M a r - A p r 2 015 | V I N E YA R D & W I N E RY M A N A G E M E N T 7 5 HEADS AND TAILS There are two types of stills: column (Figure 1) and pot (Figure 2). Each uniquely separates etha- nol from other organic compounds present within the wine. The separation of ethanol from water is based on boiling-point temperatures, as ethanol boils at a lower temperature than water. When heat is applied to the base wine, ethanol vaporizes before the water, rising to the top of the still where it collects and is sent through a condenser where it is quickly cooled, returning to a con- centrated alcoholic liquid state. The water and other organic com- pounds are later removed from the heated unit of the still as waste product. Pure water boils at 100°C and pure ethanol boils at 78.5°C (0°C = 33.8°F). There are other compounds present in the wine mixtures that will boil at varying temperatures below 78.5°C, between 78.5°C and 100°C, and above 100°C (Table 1). The first compounds to boil off (at lower temperatures) are often low compounds have boiled off, ethanol is vaporized. This portion of the dis- tillate is referred to as the "hearts." This is the part of the distillate that can be consumed and used in pro- duction of spirits. Following etha- nol, the end distillate is called the "tails" and is also an undesirable molecular-weight organic com- pounds such as methanol. These compounds are undesirable in the collected distillate. This portion of the distillate that is collected in the beginning of a still run is referred to as the "heads" or "forerun." Once the low molecular weight Column stills can distill proofs as high as 95% alcohol by volume. Photo: Thinkstock This pot still is used to make whiskey at Willett Distillery in Bardstown, Ky. Photo: Denise M. Gardner + Wine faults such as Brett- anomyces and volatile acidity are common prob- lems that every winemaker must face. + With careful distillation techniques, ethanol can be successfully separated from many undesirable compounds found in faulted wines. + The distillate can then be used to produce products such as brandy and fortified wines. + Sulfur-containing com- pounds can have negative effects on distillates, and might not be removed effec- tively by distillation alone. AT A GLANCE FIGURE 1 FIGURE 2