Etymology From Middle English ulage, from Anglo-Norman ulliage, from *ullier (“to fill a partially empty cask”), from Old French oel (“bunghole”, literally “eye”), from Latin oculus (“eye”). See French ouillage.
1
Beverages, Food, Lifestyle, Oenology, Wine In a wine bottle, the empty space between the cork and the top of the wine.
2
In a cask or barrel, the empty space, occupied by air, that is created by not completely filling the cask or barrel, or through spillage.
Alcohol production
The dry ullage will be obtained in the same manner, the dry inches being used instead of the wet.1840, Joseph Bateman, The Excise Officer's Manual and Improved Gauger:
In an industrial setting, the empty space in a tank, especially as for fuel.
Upon completion of loading, all cargo tanks shall again be inspected and ullages carefully measured and recorded, with temperatures, in the Cargo Record Book, Port Log and Supplementary Loading and Discharging Report.1950, Marine Regulations, Esso Shipping Company, page 234:
According to the Colombian Government's report regarding this accident, the bomb explosion itself did not compromise the structural integrity of the airplane; however, the explosion punctured the CWT and ignited the Jet A fuel/air vapor in the ullage, resulting in the destruction of the airplane.2000 August 23, National Transportation Safety Board, “1.18.1 Accident Record and History of Fuel Tank Fires/Explosions on Airplanes”, in Aircraft Accident Report: In-flight Breakup Over the Atlantic Ocean, Trans World Airlines Flight 800, Boeing 747-131, N93119, Near East Moriches, New York, July 17, 1996, archived from the original on 11 Jul 2022, page 180:
5
Additional cargo of little or no value taken on to prevent movement or shifting of the purposive cargo.
[…]5 hhds. rum/ 5 bbls. flour/ 1 bbl. sugar/ 9 do. pork/ 1 do. suett/ 3 do. cocoa/ 6 do. peas/ 2 ullage bbls. vinegar[…]1815 Niles Weekly Register volume 8, Supplement, p. 152. From an inventory of the frigate Confiance
6
In plural, Obsolete, Slang Leftover wine surreptitiously drunk by waiters as they clear away the glasses.
Mopps […] was draining his vast array of wine-glasses, lest the waiters carrying them off should find any "ullages" in them for surreptitious tippling on stair-cases.1862, Temple Bar: A London Magazine for Town and Country Readers, page 13:
Etymology From Middle English ulage, from Anglo-Norman ulliage, from *ullier (“to fill a partially empty cask”), from Old French oel (“bunghole”, literally “eye”), from Latin oculus (“eye”). See French ouillage.
1
To gauge the amount of empty space between the top of a cask and the level of liquid inside it.
Alcohol production
The Duties on Spirits in England are charged on the number of proof gallons they contain, which is ascertained by first “gauging” or “ullaging” the liquor, and then “trying its strength” by Sike's hydrometer, in the way already described […]1856, Arnold James Cooley, A Cyclopaedia of Practical Receipts and Collateral Information in the Arts: