Meaning of sinking jar in English:

sinking jar

noun

rare
  • A container used to determine the specific gravity of wort and wash during the brewing and distilling processes, consisting of a tin container weighed down with lead which is allowed to sink to a particular depth and then unsealed by means of a cord attached to a cork.

    Sinking jars were typically used by excise officers to determine how much excise should be charged on a particular batch of spirits.

Origin

Mid 19th century.