Rum production is based on traditional styles that vary between locations and distillers.Sugarcane is harvested to make sugarcane juice and molasses. Most rum produced is made from molasses. Within the Caribbean, much of this molasses is from Brazil. A notable exception is the French-speaking islands where sugarcane juice is the preferred base ingredient. Yeast and water are added to the base ingredient to start the fermentation process. While some rum producers allow wild yeast to perform the fermentation, most use specific strains of yeast to help provide a consistent taste and predictable fermentation time. Dunder, the yeast-rich foam from previous fermentations, is the traditional yeast source in Jamaica. ;The yeast employed will determine the final taste and aroma profile. Distillers that make lighter rums, such as Bacardi, prefer to use faster-working yeasts. Use of slower-working yeasts causes more esters to accumulate during fermentation, allowing for a fuller-tasting rum. Distillation as with all other aspects of rum production, there is no standard method used for distillation. While some producers work in batches using pot stills, most rum production is done using column still distillation. Pot still output contains more congeners than the output from column stills and thus produces a fuller-tasting rum. Aging and blending Many countries require that rum be aged for at least one year. This aging is commonly performed in used bourbon casks, but may also be performed in stainless steel tanks or other types of wooden casks. The aging process determines the coloring of the Rum. Rum that is aged in oak casks becomes dark, whereas Rum that is aged in stainless steel tanks remains virtually colorless. Due to the tropical climate common to most rum-producing areas, rum matures at a much faster rate than is typical for Scotch or Cognac. An indication of this faster rate is the angels' share, or amount of product lost to evaporation. While products aged in France or Scotland see about 2% loss each year, rum producers may see as much as 10%. After aging, rum is normally blended to ensure a consistent flavor. Blending is the final step in the Rum making process. As part of this blending process, light rums may be filtered to remove any color gained during aging. For darker rums, caramel may be added to the rum to adjust the color of the final product.
Light Rums, also referred to as silver rums and white rums. In general, light rum has very little flavor aside from a general sweetness, and serves accordingly as a base for cocktails. Light rums are sometimes filtered after aging to remove any color.
Flavored Rum: Manufacturers have begun to sell rums which they have infused with flavors of fruits such as mango, orange, citrus, coconut or lime. These serve to flavor similarly themed tropical drinks which generally comprise less than 40% alcohol, and are also often drunk neat or on the rocks.Overproof Rum is rum which is much higher than the standard 40% alcohol. Most of these rums bear greater than 60%, in fact, and preparations of 75% to 80% abv occur commonly.