What is a Column Still? How is it used in Japanese Whisky?

Hello, I'm happy to discuss this topic with you. The continuous still (Column Still) might sound very technical, but it's actually quite simple to understand.

What is a Continuous Still?

You can imagine it as a "whisky production assembly line".

Let's first talk about its sibling – the pot still. This is the short, stout, copper-pot-like apparatus. A pot still is like a pot in your kitchen; it can only process one batch of "raw material" (fermented wort) at a time. After one batch is distilled, the pot must be cleaned before a new batch can be added and the process restarted. This batch-wise process is less efficient but retains a lot of the raw material's flavor, which is why single malt whiskies are almost exclusively made using it.

The continuous still, as its name suggests, can perform distillation continuously. It looks like a tall metal column, divided into many sections internally, each with perforated plates.

Here's how it works:

1. 'Raw material' enters from the middle: The fermented "wash" (a beer-like liquid) is continuously pumped into the upper-middle section of the column.
2. 'Steam' rises from the bottom: Hot steam is blown in from the bottom of the column.
3. 'Alcohol' takes the elevator: When the steam encounters the wash, it heats the alcohol within (which has a lower boiling point than water) into vapor. Alcohol vapor is light and rises. As it reaches the plate above, the temperature drops slightly, causing it to condense back into liquid. Then, it's reheated by the hotter steam below, turning back into vapor and continuing to rise.
4. Repeated purification: This process of "turning into vapor -> condensing into liquid -> turning back into vapor" is like taking an elevator up floor by floor. With each ascent, the alcohol's purity increases, leaving water and other impurities behind.
5. High-purity alcohol emerges: Finally, the highly pure alcohol vapor collected at the top of the column, once cooled, becomes the spirit we need, with an alcohol content often exceeding 95%.

To summarize the characteristics of continuous stills:

• Efficient: Like an assembly line, it operates 24/7, producing massive quantities.
• High alcohol content: Capable of producing very pure alcohol with extremely high proof.
• Clean flavor: Due to its high purification efficiency, it filters out most of the raw material's flavors (both good and bad). Therefore, the spirits produced are typically lighter, cleaner, and smoother, almost like a "blank canvas".

How Japanese Whisky Uses It?

When we talk about Japanese whisky, we often think of single malt whiskies from Yamazaki and Yoichi, made using pot stills. However, the continuous still plays a crucial 'supporting role' in the landscape of Japanese whisky.

Its primary use is in the production of grain whisky.

You might ask, what is grain whisky? Simply put, it's whisky made from grains like corn and wheat, distilled using a continuous still.

So why produce this light-flavored grain whisky? The answer is for 'blending'.

Many famous Japanese whiskies we drink, such as Suntory's "Hibiki" or Nikka's "From the Barrel", are blended whiskies.

You can understand this relationship as follows:

• Single Malt Whisky (made with pot stills): Like paints used in a painting. They have distinct personalities, complex and rich flavors; some are smoky, others fruity.
• Grain Whisky (made with continuous stills): Like the canvas or a blending agent for a painting. It has a light flavor and smooth texture, perfectly complementing and connecting various "paints", making the entire painting (the bottle of whisky) harmonious, balanced, and easy to drink.

Japanese whisky masters use the pure and smooth grain whisky produced by continuous stills as a base, then carefully select and blend in single malt whiskies of different styles, ultimately creating blended whiskies that are rich in layers, mellow in taste, and full of Eastern Zen.

Here are two specific examples:

1. Suntory: They have a dedicated distillery called Chita, which uses continuous stills to produce grain whisky. A significant part of the mellow base you taste in "Hibiki" is attributed to the grain whisky from the Chita distillery.
2. Nikka: They are even more distinctive, having preserved two very old "Coffey Stills" at their Miyagikyo distillery. These older stills are not as efficient as modern continuous stills, but they retain more of the sweet, grainy flavors than modern continuous stills. Nikka has even directly launched products like "Nikka Coffey Grain" and "Nikka Coffey Malt", allowing people to directly experience the unique flavors brought by this type of still, which are very popular.

Therefore, overall, the continuous still is an indispensable key tool for Japanese whisky in achieving its "beauty of harmony" and "art of blending". The grain whisky it produces serves as the silent yet gentle cornerstone behind those world-renowned blended whiskies.