"Oh overflowing cask, you give drink and fill to drunkenness every loving desire. You give joy and illumine all our understanding" (Catherine of Siena, 1347-1380, qtd. in
An Anthology of Christian Mysticism by Harvey D. Egan).
The keg/cask/hogshead imps appear in
Punch, 1860. The spigot fairy appears in
Fairies and Folk of Ireland by William Henry Fros
t, 1900.