The Grains

This is where the greatness begins. We pay a premium for our high quality, non-GMO grains, but that's the only way we know how to make high quality Bourbon.

Corn

Non-GMO Corn

We have been procuring our corn from the same source for over 50 years. We also evaluate the quality of each truck load before it is unloaded. We make sure every batch is plump, clean, and sweet-smelling. And if it doesn't look or smell right, it's rejected.

Rye

More rye than most

Four Roses uses more Rye in its mashbills than most Bourbons. It's the Rye that gives our Bourbons their signature spiciness.

Malted Barley

Malted barley

Malted barley contains enzymes which are used to convert starches from the corn and rye into sugars. The yeast feeds on these sugars during the fermentation process.

The Mashbills

We employ two unique mashbills (grain recipes) in our production. One is 60% corn, and the other is 75% corn. The lower corn mashbill contains 35% rye, significantly more than other Bourbons, resulting in a spicy, full-bodied taste. Limestone-rich water from the spring-fed Salt River is added to the mashbill. Each mashbill is cooked to perfection by tightly controlling the temperature to protect the delicate flavors of the different grains.

  • Corn
  • Rye
  • Malted Barley
Mashbill E
  • Corn
  • Rye
  • Malted Barley
Mashbill B

Yeast Strains

Only Four Roses uses 5 original and proprietary yeast strains — each producing uniquely different, rich flavors.

5 Yeast Strains

Yeast strains used to create flavor

V/K/O/Q/F = Yeast strain used to create flavor characteristics.

V Light Fruitiness, Light Vanilla, Caramel, Creamy
K Light Spiciness, Light Caramel, Full-Bodied
O Rich Fruitiness, Light Vanilla, Caramel, Full-Bodied
Q Essences of Floral Aromas, Medium-Bodied
F Essences of Herbal Aromas, Full-Bodied

Yeast Propagation

Yeast propagation

Only a small volume of yeast, about the size of a pencil tip, is needed to begin the fermentation process. In the laboratory, the yeast is added to a nutrient rich medium and placed in a small vessel to grow. When enough yeast has grown, it is transferred to the dona tub to continue growing, and then finally to a yeast tub before being pumped into the fermentors along with the freshly cooked mash.

The Recipes

With the combination of 2 mashbills and 5 proprietary yeasts, 10 uniquely different Bourbon recipes are made.

Codes

O Designates production at the Four Roses Distillery in Lawrenceburg, KY.
E The mashbill that is 75% corn, 20% rye, and 5% malted barley.
B The mashbill that is 60% corn, 35% rye, and 5% malted barley.
S Designates straight whiskey distillation.
V/K/O/Q/F Yeast strain used to create flavors.

Recipes

OBSV, OBSK, OBSO, OBSQ,
OBSF, OESV, OESK, OESO,
OESQ, OESF

Fermentation

Fermentation is a metabolic process in which an organism (yeast) turns a carbohydrate (sugar) into alcohol.

Mashing/Cooking

Mashing/Cooking the Grains

Corn is added to the cooker, then the rye and malted barley are added to create the mash. The malted barley is used to convert the starches into sugars for the yeast to eat during the fermentation process.

Fermenting

Yeast is added to ferment the mash

After the mash has been cooked and the malted barley added, it is pumped into a fermentor and the yeast is added. The mash starts out sweet, but after about three days, the fermentation is complete, leaving a sour mash known as Distiller's Beer.

Distillation

Distillation is a process that separates liquids through differences in their first boiling points. Our Still converts liquids in the beer into a vapor that travels to the condenser where it is then condensed back into a liquid, thus concentrating the alcohol and desired congeners or flavoring components.

Beer Still

Column still for Distiller's Beer

This is a column still that the Distiller's Beer feeds into from the beer well and is then subjected to steam that is fed to the bottom of the still. Because alcohol boils at a lower temperature than water, the alcohol rises to the top of the column where it cooled and condensed back into a liquid that feeds off into the tailbox at about 132 proof. This alcohol is fairly clean, but still contains a small amount of impurities that effect the taste. It is sent off for a second distillation in the Doubler to remove these impurities.

Doubler Still

Pot-like still for second distillation

The doubler is a pot-like still (not a column still) where the alcohol is sent for a second distillation to remove any remaining impurities and to provide a more pure, clean taste. The alcohol comes out of the doubler at about 138-140 proof.

Tanker Trucks

Tanker trucks to ship to warehouse

After the second distillation the alcohol is sent to distillate tanks to be checked for quality and consistency, and then to tanker trucks to be shipped to our Warehouse and Bottling Facility in Cox's Creek.

Warehousing

We're the only distillery using single-story rack warehouses during the aging process to provide a gentle, undisturbed, and more consistent maturation process. The temperature varies by about 8 degrees Fahrenheit from the top rack to the bottom. Traditional metal-clad multi-story warehouses in Kentucky will vary in temperature by as much as 35 degrees.

Retention Tanks

Water is added to retention tanks to reduce the proof

After the tanker trucks arrive from the Distillery, the alcohol is pumped into retention tanks where water is added to reduce the proof from 138 - 140 to 120. Four Roses chooses to barrel lower than the legal maximum of 125 proof for quality reasons.

Oak Barrels

Charred, new American oak barrels

In accordance with the requirements for making Bourbon Whiskey, we use charred, new American oak barrels. Once the distillate has been proofed it is loaded into barrels, bungs are used to seal the barrels, and the barrels are put up in racks in the warehouse. Each barrel holds 53 gallons of distillate. Each barrel is stenciled noting the identifying batch information and recipe.

Aging/Maturation

Each barrel ages for at least 5 years

By law, the distillate must be put into new charred American white oak barrels at no more than 125 proof. Four Roses ages each barrel for at least 5 years. During that time the charred barrel will add oak and woody flavors to the Bourbon, as well as sweet vanilla and toffee notes from the carmelized sugars that are produced during the charring process. Each barrel ages differently, and is allowed to age until the desired taste profile is reached for the intended product.

Bottling

After each barrel has been carefully aged to maturity, it is bottled. Our Single Barrel Bourbon is given a handwritten label noting the warehouse and the rack location where the barrel was aged.

Testing

A thief is used to extract samples to be tasted

From time to time during the aging process, barrels are pulled to check maturation progress. A thief is used to extract samples to be tasted.

Dumping

The bung is removed and the Bourbon 'dumped' into a stainless steel trough

Once barrels have aged to perfection they are removed from the warehouse to be dumped for bottling. The bung is removed and the Bourbon "dumped" into a stainless steel trough. It is then proofed, tested, and chill filtered to remove sediment, and then sent to the bottling line.

Mingling

Different combinations of Bourbon recipes are expertly mingled together at various proportions

To offer consistency and uniquely different expressions, each Four Roses product is produced from a unique formula containing different combinations of Bourbon recipes. The required recipes are carefully and expertly mingled together in the proper proportions in the holding tank prior to bottling.

Enjoy