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Step 1
Bourbon mash in the mash tubTo begin the process of bourbon production, Indian corn is ground into meal. The meal is mixed with limestone spring water and cooked at a high temperature in a "mash tub." The distiller lowers the water temperature and adds ground rye for a second cooking. Again, the temperature is lowered and barley malt is added to the mix for the final cook. Finally, the mash is cooled to 55 to 60 degrees in preparation for fermentation.
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Step 2
Yeast is added to the mash for fermentation, which takes place in large tubs (traditionally made of cypress wood, but now more commonly made of stainless steel). During this process, the grain sugars are converted into alcohol and carbon dioxide. After three to four days of fermentation, the mash is now ready for distillation.
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Step 3
Bourbon distillation stillsDistillation is the process by which the alcohol is separated from the mash by heating the mash and collecting the vapor. The mash is transferred into a series of stills for heating, where its vapors are collected and cooled for conversion back into liquid form, or "low wines." The spent mash is no longer needed for bourbon creation and is often used as animal feed.
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Step 4
Most bourbon is distilled a second time to produce a higher-proof spirit and to improve the quality. The process is the same as the first distillation, but smaller stills are used. The resulting spirits are now called "high wines" or "white dog." This new whiskey is crystal clear.
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Step 5
Bourbon barrelsBourbon's amber color and a caramel flavor are developed in the aging process, which takes place in a new, charred white oak barrel. Seasonal temperature changes cause the barrels to expand and contract, causing the bourbon to flow into the wood itself, imparting the bourbon with color and flavor. All bourbon must age for at least 2 years, although most are aged for at least 4 years.
