There are seemingly countless random terms associated with whiskey. And while we could use a whole article to write about them (and we have), today is all about one in particular. What exactly is sour mash, and what flavors does it bring to the whiskey?
In my career, I’ve spent a lot of time learning about different whiskey-related terms. “Sour Mash” is a term that commonly adorns whiskey bottles, especially in Tennessee, on bottles of Jack Daniel’s and George Dickel. But what is it?
What is sour mash?
You’ll see the words “sour mash’ written on a bottle of whiskey when it’s made using the technique of mixing spent mash from a previous batch with new grains and water prior to fermentation. There are a variety of benefits of the sour mash process.
Why it’s used
First, since it utilizes spent mash, the process uses less water than traditional mashing and provides consistency from batch to batch along with reducing the risk of bacteria due to the more acidic environment.
“It adjusts the pH environment in the cooker to allow the natural enzymes from the malted barley to provide the best enzymatic activity to convert grain starches to simple sugars,” says Michter’s Master of Maturation Andrea Wilson.
She adds, “The alternative is a sweet mash, sometimes referred to as water mash. In this process, the water and milled grains are introduced without any backset from the previous batch. This process can provide a less consistent flavor profile and can be more challenging to manage due to the risk of bacterial growth.”
What is the history of sour mash?
There’s a long history of sour mash whiskeys in Tennessee, Kentucky, and beyond. In fact, the process has been used almost as long as whiskey has been produced in the US.
“Catherine Carpenter of Casey County, Kentucky, was the first to document both the sweet mash and sour mash recipes in 1818,” says Wilson.
What it tastes like (or doesn’t)
When it comes to sour mash whiskeys at Michter’s in particular, discipline of quality is embedded in their process at every step.
“We make our whiskeys in Kentucky according to the traditional Sour Mash process described above which does influence the taste profile to be more consistent due to the chemical changes associated with a portion of the previous batch.”
It should be noted that the sour mash technique doesn’t specifically add any flavors to the whiskey’s overall palate. It does impact the profile because the extra, acidic spent mash adds to more yeast growth and a richer, sweeter, and more complex whiskey.
Final takeaway
While the sour mash itself is important to many whiskeys, according to Wilson, high-quality water is an essential ingredient in making high-quality whiskey.
“The natural geography of Kentucky is such that we sit on a limestone aquifer. The natural filtering of the water through the limestone aquifer removes minerals like iron and manganese, which can be very disruptive to the natural enzymes. Additionally, the water for making whiskey imparts calcium, which helps to balance pH and acts as a fortifying agent for our yeast.”
