Because of the low thermal conductivity of coal and the slow rate of distillation, coking is a slow process.

因为煤的导热性低、蒸馏的速度慢，所以炼焦的过程较慢。

youdao

The guides, like those at Maker's Mark, stress the use of traditional methods: the slow fermentation of sour mash in vats made of cypress, the distillation in copper-pot stills (Labrot and Graham use three instead of the usual two), the regular sampling of barrels by discriminating imbibers with decades of experience, to achieve just the right taste.

ECONOMIST: Making bourbon fashionable