What Is Sour Mash Whiskey? (2023 Updated)

Last Updated on August 22, 2023 by Lydia Martin

The sour mash method has become a crucial process for a distilled spirit like whiskey. Experts believed that Dr. James Crow was the first to introduce the sour mash method for many years. But a new written record proves it otherwise.

The history of the sour mash method is quite uncertain. What is sour mash whiskey? How does it affect the final taste of our favorite liquor?

All About Sour Mash Whiskey

Sour Mash Whiskey

Sour mash whiskeys combine the spent mash from a previous batch and a new mash to control the growth of bacteria that can alter the taste of the liquor. The old mash is a previously fermented mash containing dead yeast, a good food source for live yeast.

The name came from the sourdough starter or the mixture of flour and wheat, a method used to create bread. 

Fun Facts

Fun Facts

What Is A Mash?

A mash is mixing ground grains (typically rye, corn, malted barley, and wheat) with water and yeast. The mixture will go through the fermentation process to produce alcohol. 

It is an important step for distillers. They had to carefully regulate the pH level of their fermented grain because a higher pH level can cause unwanted bacterial growth.

What Is Souring?

Jack Daniel's Sour Mash Whiskey with glass

Souring is a process of introducing acid to the mash mixture that causes physical and chemical changes, such as adjusting its pH level. It makes the mixture more receptive to yeast, which helps during fermentation.

The souring technique adapts its name from sourdough starter, which is a process involved in making bread.


Its Importance To The Whiskey-Making Process 

Most distillers widely use sour mash in making whiskey because of its benefits. One clear importance of this process is reducing the pH level of the mash mixture to prevent the risk of infection and spoilage in every batch released.

Alcohol connoisseurs have a sensitive palate where they notice the liquor’s slightest flavor change. That’s why sour mash is also favorable for consumers because it offers consistency in the flavor profile of their whiskeys.

Why Distilleries Use The Sour Mash Technique

Sour Mash Whiskey Distillation Process

Most distilleries use the sour mash technique to have more control in balancing the pH levels of their mash in every batch. The ideal mash pH level to keep the mash acidic is around 5.0 to 5.5.

The sour mash process also helps maintain a constant tasting profile for every batch of releases. It produces the highest quality spirits with tangy and strong flavors.

Does Sour Mash Make Whiskey Taste Sour?

No, the sour mash process does not make whiskey taste sour. This distillation process causes most major bourbon whiskey products to have strong flavors of caramel, vanilla, spices, and oak.

Jack Daniel, the most famous Tennessee whiskey labeled as sour mash, has the initial tasting notes of vanilla, walnut, corn, and banana. It has a soft and smooth palate with some traces of cinnamon and smoke.

Do All Whiskey Distilleries Use Sour Mash?

Whiskey Distillery Still Pot

No, the majority of whiskey distillers use sour mash but not all. And some major companies do not present their products as sour mash.

Sour mash is a technique similar to the bread-making sourdough starter. It introduces some spent mash into the new mash with a 1:3 or 1:4 ratio. The distillers will let the mash sit for at least seven to ten days before distillation.

Read: Recommended Whiskeys Below $100


Who invented the sour mash method?

Catherine Spears Frye Carpenter invented the sour mash method in 1818 [1]. However, the use of spent wash called dunder already started in Jamaica for rum production in the 1700s. Many believe that this method is the origin of sour mash.

Is Jack Daniels whiskey or sour mash?

Jack Daniel is a whiskey using the sour mash method. It is a product made of grain mash composed of 80% corn, 12% malted barley, and 8% rye. After distillation, it undergoes Lincoln County Process, setting it apart from a sour mash bourbon.

Key Takeaways

Sour mash whiskey is a common phrase among American bottle labels. This process does not impart a sour taste to the liquor. Instead, it regulates bacterial growth and ensures a consistent flavor profile in every batch of whiskey made.

The first person to have a recorded recipe for the sour mash process was Catherine Carpenter in 1818. Like bourbon and Tennessee whiskey distilleries, almost all American whiskey use sour mashing during their whiskey production process.



Lydia Martin

Lydia Martin hails from Redmond, Washington, where you’ll find some of the best cocktail bars and distilleries that offer a great mix of local drinks. She used to work as a bar manager in Paris and is a self-taught mixologist whose passion for crafting unique cocktails led her to create Liquor Laboratory. Lydia can whip up a mean Margarita in seconds! Contact at [email protected] or learn more about us here.

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