Walk into a still house and the equipment tends to command your attention. One still may have a broad copper body and a long, elegant neck. Another rises in a column. A third seems to combine the two.
Their shapes are interesting because they give vapor and liquid different places to meet. To understand what each system does, follow what goes in, what comes back, and what leaves.
Three Ways To Organize The Journey
In a pot-still batch, the vessel receives one charge of liquid. As the run proceeds, both the liquid left in the pot and the spirit being collected change. The distiller works with that changing run, sometimes using successive distillations before selecting the spirit to carry forward.
In a continuous column, feed enters while other streams leave. Vapor rises and liquid descends through contacting stages. The system keeps that exchange going during operation. Column designs serve a range of spirits, including bourbon and grain whisky. See equipment examples: Forsyths — Column Stills.
A hybrid combines pot and column features. In the illustration, a single batch supplies vapor to a column, and a partial condenser returns some liquid down through it. Other arrangements offer selectable paths through the equipment. Explore the combinations: Forsyths — Hybrid Stills.
That third example is especially useful: a column can work with one changing batch. “Column” describes equipment, while “continuous” describes how a system operates.
Each arrangement gives the distiller ways to change the balance of compounds carried onward. The fermented liquid, the amount of separation, and the portions collected all contribute to the spirit that emerges. Strickland — S1, pp. 197–215, 217–237, 239–249 and 251–256.
Look A Little Closer
The three details in this picture help explain why the whole path matters.
First, notice the liquid returning down the neck. A tall neck, a swelling in the head, and the angle of the lyne arm change where vapor loses heat and where condensed liquid travels. Liquid flowing back toward the pot meets rising vapor again; liquid moving toward the final condenser continues toward collection. Heating, charge, and cooling conditions help shape that movement.
Some still heads have wonderfully specific names: ogee, lamp glass, and boil ball. Look at their profiles and you can begin to see what the names are describing. Compare the shapes: Forsyths — Pot Stills; Strickland — S1, pp. 197–215.
Next, consider the copper surface. It conducts heat, but it also participates in chemistry that can reduce some sulfur-related aromas. In research on malt-whisky pot stills, changing which parts of the system contained copper changed the resulting spirit’s composition and aroma. That makes “Where does the spirit meet copper?” an interesting question on a distillery visit. Harrison, Fagnen, Jack & Brosnan (2011), pp. 106–112 — copper location and new-make aroma.
Finally, follow the cooling. A worm tub carries vapor through a long coil surrounded by cooling water. A shell-and-tube condenser provides heat-transfer surface through a bundle of tubes; the picture shows its outer housing. In both, water and spirit take separate paths. Geometry and operating conditions affect heat transfer and copper contact along the way. Compare condenser designs: Forsyths — Condensers.
Choosing Portions Of A Changing Run
Imagine the spirit from a batch run collected in a long sequence of small samples. As you move along the sequence, the balance of compounds changes. Some become more prominent while others recede.
The familiar words heads, hearts, and tails describe portions selected during that changing run. Each portion contains a mixture. Choosing where one collection ends and another begins changes what is combined in the spirit carried forward; recycling decisions also affect the process.
A musical chord offers a useful comparison. Several notes sound together, and changing their relative loudness changes the character of the chord. Selecting a portion of the run similarly selects a changing combination of compounds.
These selections do not provide a universal temperature or discard amount that makes an unknown spirit safe, and tasting cannot certify contaminant safety. Strickland — S1, pp. 175–195; source discussion and qualification of p. 194.
Meet The New Make
The spirit emerging from distillation, before maturation, is often called new make. It offers a chance to explore the character that will enter the cask.
The useful question is what the producer wants that spirit to become. A new make intended for a particular maturation plan may emphasize characteristics that will develop alongside the wood. Assessment begins with the starting spirit’s own quality and character, then considers that destination.
For a comparison, identify the samples and production lots, record their strength and preparation, and use matching presentation conditions. Describe the aromas, tastes, and texture before deciding which you personally enjoy. Then connect those observations to the intended style. Strickland — S1, pp. 257–267 and 269–272; chapter 23 closing discussion.
On a visit, try asking: “What character are you trying to retain, and which parts of this system help you retain it?” The answer can connect a copper shape in front of you with a flavor you later notice in the glass.
Try Tracing A System
A vessel receives one charge of fermented liquid. Vapor rises from it through a column, and some condensed liquid returns down that column. The charge changes as the run proceeds.
How would you describe the operation? What would you record before comparing its new make with another sample?
For your bottle record, add any still and operating details the producer supplies. You now have the vocabulary to follow the spirit from fermentation through distillation. Next comes the cask—and another set of choices that will change it over time.
Two terms for the next example: In a common two-stage pot-distillation process, low wines are the distillate from the first run, collected for a further distillation. Feints are fractions retained for redistillation; usage varies between producers. Follow the stated stream rather than relying on its name alone.