The
Facts About Fining Agents
Fining
agents work on the principle that all of the particles clouding up wine
or beer have an electrical charge. As the saying goes, opposites attract,
so a positively charged fining like gelatin will attract negatively charged
particles and bind with them, making them too heavy to float. |
| Fining
agents are used to clarify wine and beer before bottling
or long-term storage. Fining (pronounced fine- ing) agents work on the
principle that all of the particles clouding up wine or beer have an electrical
charge. As the saying goes, opposites attract, so a positively charged
fining like gelatin will attract negatively charged particles and bind
with them, making them too heavy to float. They will then sink to the bottom
of your carboy, leaving everything brilliantly
clear. Well, that's the theory. In practice, finings might not work on
the first try, or it may take more than one kind of fining to clear a wine
or beer. |
Bentonite Primer
Bentonite
is a fining agent. Fining is the action of removing particles that make
a haze in wine by combining them with materials that bind to them and force
them out of suspension, leaving the wine clear and bright. It not only
improves a wine's appearance; it also makes sure that it is stable. Stable
means that it won't change if appearance, taste, aroma, or chemical composition
while in storage. |
| Bentonite is a type of clay,
known as aluminosilicate. Its technical name is Montmorillonite. It's found
with various minerals attached to it, such as sodium, calcium and magnesium.
It was originally found in Fort Benton, Wyoming (where the name came from).
It's used in winemaking, beauty treatments, mineral extraction, water treatment,
and kitty litter. |
| When used in winemaking,
it is stirred into the wine to remove proteins and other haze causing particles.
It works through adsorption. This means that it attaches itself to a particle,
and together they are too heavy to stay in suspension, falling to the bottom
of the carboy, leaving the wine clear and stable. Bentonite settles out
so completely that it does not leave any residue of taste or color behind. |
| Our
wine kits have you add bentonite on the first day. This is one of the
fundamental differences between kits that you may have noticed. The reasons
behind it go beyond technology, straight into winemaking philosophy. When
bentonite is added on the first day, it disperses through the wine and
most settles to the bottom within a few hours. At the end of 48 hours,
however, the bentonite is back in circulation. This is because of the process
of gas nucleation that the CO2
in the wine is undergoing. |
| As the yeast
ferments the sugar, it converts it into carbon dioxide (CO2)
and alcohol. The bubbles of gas don't actually appear out of nowhere. They
want to come out of suspension on some kind of a point, where a nucleus
of gas can form the beginning of a bubble. Thus we get the term 'nucleation'.
This point could be a scratch in the carboy, a bit of grape material, or
a particle of bentonite. The bentonite is surrounded by a bubble of gas
and floats up to the surface of the wine. When the bubble bursts, the particle
of bentonite drops back down to the bottom of the carboy, all the time
working to adsorb the other particles clouding the wine. In this way, the
bentonite is circulated around the wine continuously for days, doing its
job. |
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