Column still for whisky distillation
It looks like chemical tank tower.
It enables multi step distillation in column(tower) as continuous line production. Alcohol distilled by column still is smooth flavor and clear taste.
Distillation of almost all grain whisky is done by column still.
Vodka, Base spirits of gin and liquor, Shochu Kou type, Marc and light rum are also made by Column still.
Inside of Column
There are many steps in column. Mash is injected in middle steps and flowing down to lower steps. There are many small porous on steps which steam pass through.
Mash on the step is heated by steam from lower step. Alcohol and water are evaporated from mash and going to upper steps. Steam heating mash is going back to liquid and falling down to mash
Due to above process, mash/liquid and steam in upper floor has higher alcohol than lower floor.
Coffey column still
First column still was developed in 1826 in Ireland by Robert Stein.
Aeneas Coffey developed improved column still "Coffey still" in Ireland and applied patent in 1830(Approved in 1831). But distilleries in Ireland were very conservative and stick to conventional pot still. Therefor he moved to England in 1835 and Coffey still became popular in 1840s for white spirits to make Gin.
Just 1 year after his death in 1852, blended whisky was approved and grain whisky made by Coffey still became main material of Scotch blended whisky. Blended scotch took market share from Irish single pot whisky made by traditional pot still.
There are only less than 10 column stills working today in the world and 2 of them are in Miyagikyo Nikka. There were one more coffey tye column still in Kawasaki distillery of Ocean group.
Super Arosupasu column still
There were several improved column still after Coffey still like Irguez type, Guillaume type and Grimma type however most remarkable is Arosupasu type by Usine de melle company in France in 1950. Improved Super Arospasu type was also developed in 1955.
It can remove fusel oil which makes uncomfortable flavor from spirits by Hydrolytic distillation. After Super Arospasu type, there were some improved type like decompression type, although Super Arospasu type is standard method of not only grain whisky but also world spirits today.
Suntory and Kirin chose this productive column still when they buit their new grain whisky distilleris(Chita and Fuji Gotenba) in 1973.
Takara group is also using it for Schocu and other spirits.