From en.wikipedia.org:
[Peg used to control airflow in casks of ale] [date=November 2023] [the
riverbank erosion prevention technique] Various beer barrels with wooden
spiles (round knobs on cask) in addition to beer tap s. A SPILE (sometimes
called a "cask peg") is a wooden or metal peg used to control the flow of air
into, and carbon dioxide out of, a cask of ale or wine.[1][2] Spiles can also
be used to broach liquids (like maple syrup) from a tree.[3]
** Ale use
Cask ale is dispensed without the addition of externally supplied gas.
Properly conditioned cask ale will have enough dissolved carbon dioxide
(produced by yeast) to have bubbles.[1] In fact, the yeast can produce more
carbon dioxide than is required, and it is for this reason that the cask is
vented through the hole in the shive.
The cask is sealed when it is first connected to a beer engine. It has a
keystone (where the beer tap will be driven in) and a shive (through which it
was filled). Once it has been laid down for dispensing, a venting punch is
used to pierce the shive, which is either partially pre-drilled or has a
hardwood tutt[reason=similar to tuft] sealing the completely drilled hole.
This breaks the seal, and the tap can then be driven into the keystone.
To allow the loss of excess gas, a soft spile (made of open-grained softwood,
bamboo, or harder wood with cuts in) is used.[4] Once a cellarman judges this
process to be complete, a hard spile is inserted which does not allow any more
gas out. These are made of harder wood (usually still technically "softwood",
but denser and more solid than a soft spile). When beer is being drawn from
the cask a hard spile is removed and can be replaced by a soft spile, or left
open. When no beer is being dispensed a hard spile is put back in. Plastic
spiles are also available.
Once a spile is reinserted, enough gas will be generated by the yeast to
replace the volume of gas that will have come out of solution. But the amount
of carbon dioxide that can be produced is limited, so a hard spile is kept in
as much as possible. This is one of the reasons for real ale's short
shelf-life once a cask is opened – if too much carbon dioxide is lost, the
beer will become flat. Typically, the beer will be good only for two to four
days[2]; this short shelf life is why it is important that a pub serving real
ale have sufficient turnover for casks to be emptied while still at their
best.
** Other uses for term
A spigot (or "spile") extracting syrup from a maple tree. Like many such
older terms, the word spile has other local meanings. For example:
- A wooden stake or fence post.
- A tapper, [5] an implement used to tap any sort of tree (e.g., for birch sap , maple syrup , rubber tapping , or palm wine from a toddy palm ).
- An iron or wood spigot driven into a sugar maple to produce maple syrup . [6] <ref name="sugar"/>
- At Indian Harbour in Nova Scotia, the shores on which fish processing "stores" were located were called spiles. [date=November 2023]
- A term used in boatbuilding to describe the means/actions which a builder uses to determine the shape of any curved piece needing to be fitted to a curved surface. [date=November 2023]
** In popular culture
A spile is utilized to obtain water in the novel _Catching Fire_ (2009) and
subsequent film _The Hunger Games: Catching Fire_ (2013).[date=October 2022]
The spile consists of a tube with one end sharpened and the other split. When
pounded into a tree, a stream of fresh water flows from the tube. Most of the
year, this is not consistent with the nature of trees, as water diffuses
upward through very tiny capillary passages. When a tree is cut down, water
does not flow out of the cut surface. The technique used in the movie would
only work in early spring or late winter, when the watery sap runs high in the
trees.[date=October 2022]
The taps that are placed in maple trees are placed into drilled holes and the
resultant fluid is sap, not water.[date=October 2022]
** See also
- Beer tap
- Cask breather
- Stopper (plug)
- Bunghole
- Keystone
- Spigot
** Notes
[1] [2]
** References
[1]
** Bibliography
- [title=Cellarmanship - Caring for Real Ale ]
** External links
[image1= Maple Spile in Tree (see
https://www.flickr.com/photos/chiotsrun/4375300279) < !--CC BY-NC 2.0-->]
- [wikt-inline]
- [Category:Spiles]
Category:Brewing Category:Tree tapping