How is bourbon distilled?

What is bourbon? In a nutshell, bourbon is a whiskey made from main corn and is aged in charred oak barrels. It has a sweet taste with a tad of smokiness that is obtained from the charred oak barrel.

As a bourbon enthusiast, you have an idea of how it is made, but then it is just a rough idea that you have mulled over as you swirl your bourbon in the glass. Humans are generally made to be very curious, and that is why it is not odd to try and find out how that drink you love so much found its way into the bottle.

When you think about it, you will understand that the bourbon you come to enjoy as a process dependent on the following; “the grain, the yeast strains, the new white oak barrels, and the storage.”

Let us take a journey through the distillation process that makes a good bourbon.

First, what goes into bourbon?

Bourbon, just like any other whiskey, is made with grains. The makeup, sort of recipe of this grains, is known as a ‘mash bill’. These grains are corn, wheat, rye, and barley. Corn should be the majority in making a good bourbon at least “51% of the mash bill.” Some manufacturers even use corn only to make their bourbon, though rare. The other grains that go into this production are called “flavoring grains.” Barley is used in its malt form mostly in a small percentage to help in the fermentation process. Rye and wheat are also added, although not together.

The difference between adding rye or wheat in your recipe is the type of bourbon you will come up with. Adding more grass will result in a heavy type of whiskey because rye is spicy and peppery. More wheat, on the other hand, will lead to a much sweeter kind of bourbon. Other than malted barley being an aid to the fermentation process, it adds some goodness to the recipe.

With that little knowledge, let us get to the process.

The distillation process

Bourbon is double distilled. What does this mean? It is first extracted in a “column-still” and then again derived in a “double or thumper essentially an attached continuous pot-still.”

The process starts with the malted barley, corn, wheat, and rye is ground coarsely and mixed with water. Some people use a rolling mill while others use a hammer mill. Ultimately, the grains must be coarsely ground.  The grain and water mixture is then heated to allow “Alpha Amylase enzymes naturally present in grains,” to break down the starch in the grains into small sugars that can be fermented. All the grains used in this mash bill contain Amylase, but most of it is found in malted barley. Thus it’s used.

Corn, which is the main ingredient, is mixed first with water and then heated. Next, you add either wheat or rye after the temperatures have been dropped. Barley is then added, and the temperatures further dropped and left to cook. Pressure may be added at this point.

After the cooking process, the mash is put into a fermentation area or tank, where they add yeast. An ingredient, mainly used by American producers, called ‘sour mash,” is then added. This ingredient is the remaining residue from the first process of distillation. This, they call a ‘set back’.

What is ‘sour mash’?

This is the art of taking a little amount of mash used previously and adding it to a new batch. This creates an evenness in the function of yeast from one bunch of bourn to the next. The sourness created lowers the batch’s pH, aiding the batch, aiding the yeast to ferment the batch and guarantees better bourbon fully.

There is a twist to this, called a ‘sweet mash.’ Here, there is no addition of any sour mash, but you add fresh yeast; this results in higher pH in the batch, making the yeast ferment differently, making the resulting whiskey taste individually.

The fermentation process suffers the challenge of controlling bacteria. Therefore the setback process comes in handy by reducing the level of pH. A lower pH does not give bacteria room to grow and encourages the yeast to function well.

The resulting mash looks like a “beer-like fermented slurry” is distilled. The rule of thumb here is that the mash’ should be distilled at 80% abv (alcohol by volume). Here is where they are distilled twice, first in a column or beer still, and then second in a directly heated copper pot still; these are called doublers.

After all this, the product here is known as “white dog,” which is a spirit. This is now what is taken through the aging process. It is put inside a new charred oak barrel and left to age for at least two years. A point to note is that the white dog must be made dilute using water that is demineralized to about 62.5% abv, which is alcohol by volume. The barrels must be charred inside, which ensures that the starch in the wood is converted into sugars that are caramelized. This caramelization adds some caramel and vanillin flavors to the bourbon and also gives it its color.

These barrels are put in significant buildings or sheds called rick houses, either built using wood, iron sheet, or stone.  They may be painted in colors that may help in heat conservation. Such colors are red, cream, black and brown. This makes sure that even during wintertime, the heat accumulated during the summer will not be lost.

Balancing the Temperature

Any change in temperature will affect the overall maturing of the bourbon. When it is hot, the wood expands, allowing some of the bourbon to get into the wood. During cold times the wood contracts and the bourbon gets back out of the wood. This is referred to as a cycle, and the process is what gives bourbon its color and flavor. Some production companies add more heat to increase the cycle process to make the bourbon richer in color and taste.

Next, the bourbon goes through a process called “chill filtration.” It involves chilling the bourbon in very low temperatures “between -2°C to as low as -12°C,” so that the protein molecules accumulated can be precipitated to allow for smooth filtration.

Only after undergoing all the processes above can bourbon be bottled usually at percentage alcohol by volume of 40 or higher.

As we Conclude…

The major part of the distillation process is the aging process that the bourbon goes through. This is what gives it the color and taste that you have come to enjoy so much. It is said to be legislated that for whiskey to be termed as bourbon, it must be aged in new charred oak barrels. The barrels’ charring gives the wood inside the caramel effect that gives the whiskey an oakish, vanilla and caramel taste, and a tannin (dark brownish color).

Here, during the aging process, two main factors play a key role in how the bourbon will turn out. One is the location of the rickhouse, which determines how fast the bourbon ages. Most of these sheds have an upper and a lower room. Since hot air rises, this means that the temperatures on the top room are higher than those in the lower room. This heat is best for the ultimate maturation of the whiskey. The best way to control this is to rotate the barrels from top to bottom. This way, all the barrels will experience the same temperatures.

The second factor is the climate or temperature changes. Warmer temperatures make the wood of the barrel to expand making the whiskey deep into the wood. Colder temperatures make the wood contract the bourbon gets out of the wood into the barrel. This is where the bourbon gets its dark color and oakish taste from.

To sum it up, for bourbon to be termed as good it must have undergone the following,

It is made from a recipe of at least 51% corn.

Must be aged in new charred oak barrels for at least two years

Distilled at around 80% alcohol by volume (ABV) or lower

Put into a barrel to age at 62.5% abv or lower.

Bottled at 40% abv or higher

What is ‘straight bourbon?’

The difference between a regular bourbon and a straight one is the new regulations that are required for straight bourbon. These are:

It must be aged for at least four years. If the aging time is less than four years, the same must be captured in the bottle.

It must not contain any additives such as flavors, or colors.

Now you know what goes into distilling bourbon. No matter if you are an amateur or an experienced bourbon taker, I bet this article has shed some light on the process of its production.

Much of the process involving the production or distillation of bourbon is very complex and consists of a lot of scientific jargon. This article aims to simplify the process for you, so you get to know the contents of the bottle you enjoy before actually spending your money on it.

I hope you have enjoyed your read.

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