What's the Difference Between Heads and Tails in Distillation?
In the context of distillation, "heads" and "tails" refer to different fractions of the spirit collected during the distillation process, each characterized by a distinct chemical composition, aroma, and taste, and separated from the desirable "hearts" fraction.
Understanding Distillation Fractions
Distillation is a process used to separate components of a liquid mixture based on differences in their boiling points. During this process, the distillate is typically divided into three main fractions: the "heads," the "hearts," and the "tails." These divisions are crucial for producing a high-quality, safe, and palatable spirit.
Heads (Foreshots)
The heads, also known as "foreshots," are the very first portion of the distillate to emerge from the still.
- Composition: They contain highly volatile compounds with lower boiling points than ethanol, such as methanol, acetone, and acetaldehyde.
- Characteristics:
- Aroma: Often described as sharp, solvent-like, nail polish remover, or paint thinner.
- Taste: Harsh and unpleasant.
- Toxicity: Methanol, a common component, is highly toxic and dangerous for consumption even in small amounts.
- Purpose: Heads are typically discarded or saved for re-distillation with a subsequent batch of wash. They are never bottled for consumption due to their undesirable flavors and potential toxicity.
Hearts (Potable Spirit)
The hearts are the central and most desirable part of the distillate. This is the portion that distillers aim to collect for bottling.
- Composition: Predominantly ethanol (the desired alcohol), along with a balanced mix of desirable congeners that contribute to the spirit's unique flavor profile and aroma.
- Characteristics:
- Aroma: Clean, pleasant, and characteristic of the intended spirit (e.g., gin, whiskey, vodka).
- Taste: Smooth, rounded, and enjoyable.
- Purpose: As highlighted in the reference, "Now the hearts are going to be bottled... it tastes like a great gin. But it's far too strong. So you are going to proof or water that down now watering that down or proofing that down." This indicates that hearts are the potable spirit, which are then diluted to a suitable alcohol by volume (ABV) before bottling.
Tails (Feints)
The tails, also known as "feints," are the last portion of the distillate collected.
- Composition: They contain less volatile compounds with higher boiling points than ethanol, such as fusel alcohols (e.g., propanol, butanol, isoamyl alcohol) and other heavier compounds.
- Characteristics:
- Aroma: Often described as wet cardboard, cheesy, woody, or even rancid.
- Taste: Oily, heavy, and unpleasant. They can leave a cloying aftertaste.
- Purpose: Like heads, tails are generally undesirable for potable spirits. They are typically cut off and either discarded or more commonly, saved and added to the next batch of wash or low wines for re-distillation to extract any remaining usable ethanol.
Key Differences Summarized
Here's a breakdown of the primary differences between heads, hearts, and tails:
| Feature | Heads (Foreshots) | Hearts (Potable Spirit) | Tails (Feints) |
|---|---|---|---|
| Boiling Point | Lowest (highly volatile) | Medium (ethanol, desirable congeners) | Highest (less volatile) |
| Collection Order | First | Middle | Last |
| Composition | Methanol, acetone, acetaldehyde, light esters | Ethanol, balanced esters, aldehydes, higher alcohols | Fusel alcohols, heavier compounds, water |
| Aroma | Sharp, solvent-like, nail polish remover, chemical | Clean, pleasant, characteristic of the spirit | Oily, wet cardboard, cheesy, woody, rancid |
| Taste | Harsh, unpleasant, burning, toxic | Smooth, rounded, desirable, palatable | Oily, heavy, bitter, cloying, unpleasant |
| Purpose | Discarded or re-distilled | Diluted (proofed down) and bottled for consumption | Discarded or re-distilled with next batch |
Why Separation is Crucial
The precise separation of these fractions, known as "cutting the spirit," is one of the most critical skills of a distiller. It directly impacts the safety, quality, and flavor profile of the final product. By removing the heads and tails, distillers ensure that only the pure, flavorful "hearts" make it into the bottle, resulting in a superior and safe spirit.
