How the Moor's Head Works

Fitted onto the neck of a cucurbit, the moor's head presents a curved, domed interior surface to the vapor rising from the heated liquid below. That curved surface is the whole mechanism: because the head is not directly over the fire, it stays cooler than the vapor reaching it, so the vapor condenses back into liquid the instant it touches the dome's inner wall. The condensed droplets do not fall back into the cucurbit; the dome's shape is built with a slight downward slope toward one side, so gravity carries the liquid along the curve to a narrow channel that exits through a spout projecting from the head's lower edge.

From there the distillate drips into a receiver positioned just below the spout's tip. The joint between the head and the cucurbit's neck had to be sealed well enough to stop vapor escaping at the seam, typically packed with a clay-and-cloth luting compound that could be broken and reapplied each time the still was opened. Because the head, not the pot, was where the condensing happened, swapping a plain moor's head for a taller, more sharply tapered cap like the rosenhut changed how efficiently the vapor condensed and how selectively it separated one volatile fraction from another, all without altering the cucurbit doing the actual boiling.