It's a beer world after all!
Coolship is the name given to the shallow, open vessels traditionally designed to cool hot wort prior to
fermentation.The use of “ship” in the name probably refers to the medieval practice of cooling the boiled wort (or
mash) in a hollowed-out tree trunk—not dissimilar to a primitive boat. Before the advent of refrigeration and chilled
water, hot wort was cooled by transfer to these shallow, open vessels, where the wort was allowed to cool slowly.

These open coolers or coolships with high surface area-to-volume ratios had three functions: cooling, aeration
of the wort, and separation of the cold trub. However, these open vessels were fully exposed to the air and
consequently subject to microbial contamination.

Inevitably, with larger volumes of wort to cool, the coolship dimensions necessary to achieve effective temperature
reduction became unwieldy and alternative methods of cooling (usually vertical coolers in which the hot wort
flowed continuously as a thin film over a vertical metal surface cooled with chilled water) were introduced.

Coolships still have application in the brewing of traditional Belgian lambic beers for which the large surface
area of cooling wort lends itself to spontaneous fermentation (whereby yeasts and bacteria present in the
atmosphere, and often in the fabric of the brewery, ferment the wort to create a rich assortment of interesting
and challenging flavors). These lambic coolships are often located in the roofs of brewery buildings where
louvered shutters are opened to allow entry of the surrounding atmospheric microflora (and sometimes
microfauna!) of Belgium into the coolship room.


The Ale Pole or “ale stake” was a rudimentary sign used in England in the medieval period to indicate that a
household had brewed a fresh batch of ale. In drawings from the period, it is usually depicted sticking out of a
window or hanging from a house like a flagpole. In those days all beer-making was domestic, but houses that
built a reputation for the quality of their brews might invite the people of the village to come in and drink,
becoming an “alehouse.” If the house also supplied wine, a bush of evergreens was tied to the pole.

The practice began in early medieval times and lasted until the Renaissance. It is believed that the ale pole
followed the Roman legacy of shop signs that denoted the trades practiced within. A popular inn sign still in use
in Britain is the Chequers, which stems from the Roman sign of a chequer board indicating that wine was on
sale and money could be exchanged.

Legislation in the 14th and 15th centuries to control the quality of food and drink sold to consumers had an impact
on alehouses. An official known as the “ale-conner” had to verify the quality of the beer made on the premises.
The conner visited alehouses when the owners displayed ale poles with branches or bushes attached.

The use of the ale pole went into decline as inns and taverns began to display more elaborate signs. Some signs
had religious connections, such as the Cross Keys and the Lamb, while others reflected medieval trade guilds or
associations as can be seen in the Elephant and Castle, the sign of the Cutlers’ Company. But the ale pole and
bush has not entirely disappeared. There are many pubs today called “The Bush.” The Bull & Bush in London
achieved fame during the time of the Victorian music hall with the popular song “Down at the old Bull & Bush.”


Hope you found this month's column of interest.  If you have any questions about beer or brewing
or just want to submit a word for me to discuss here just
e-mail it to me.

Thanks and Cheers!
Coolship  -  Ale Pole
A new column by
Jack O'Reilly
Jack O'Reilly attended the
famous Siebel Institute/ World
Brewing Academy in Chicago.
I'm very excited to be part of the BeerNexus team.  I think my many years in the
beer business both as a brewer and manger will enable me to explain and
investigate many topics of interest for those who really love craft beer.
Hope you join me every month.  
More by Jack: #1, #2, #3, #4, #5, #6, #7, #8, #9, #10, #11, #12, #13, #14,
#15, #16, #17, #18, #19, #20, #21, #22, #23, #24