Fining
is a method to either clarify or chemically stabilize wine, or to do both.
The procedure works by and depends upon both chemistry and gravity. Fining begins by selecting a fining
agent appropriate to the desired purpose. The agent must be heavier
than both water and alcohol and not soluble in either. The agent is then
stirred into the wine to evenly distribute it for best effect.The fining
agent ultimately settles to the bottom of the container (usually
a tank or barrel), causing small suspended particles to precipitate out
along with the agent. Afterwards, the clarified wine is then separated
off the settlings (lees) by siphoning (racking). Physical agents work by absorbtion,
sucking up the tiny particles as the agent settles towards the bottom.
Chemical agents work by adsorbtion, forming chemical bonds with
hydrogen elements in the undesired particles. Fining agents include egg
white, milk, blood, gelatin (a protein extracted from bones and tendons),
carbon, casein (the principal protein constituent of milk and cheese)
and isinglass (an extract of sturgeon bladders). Heat stabilization
is a fining process that uses bentonite (a clay of hydrated magnesium
silicates) to remove protein, which may cloud a wine. Fining agents are intended to precipitate
out and be removed, so they do not end up as components of wine, although
trace amounts may linger. The majority of wines that are fined are also
filtered which would remove even residual traces. Fining can lower high levels of tannin,
remove haze, and reduce color. Care needs to be taken to chose the proper
fining agent and amount that conforms to the wine style the winemaker
wants to achieve. Over-fining can result in wine lacking in qualities
such aroma complexity, flavor depth, viscosity, and even aging potential. When the term "unfined" appears
on a wine label, it serves as notice that the wine inside may be less
than perfectly clear and probably contain more than a usual amount of
tannin or sediment. That said, however, wineries are under no legal or
moral obligation to reveal for what purpose or whether or not a wine has
been fined and there are no legal standards or agencies to define or monitor
fining processes.
Page created February 8,
2003 | Last Updated
April 4, 2006
Except as noted, site design & content © 1999-2006 by Jim
LaMar . All rights
reserved.