Agriculture Reference
In-Depth Information
is better to make them on purpose rather than accidentally,
because their accidental manufacture is attended by some
risk.
Potassium sorbate, a semi-synthetic preservative that inhibits
fermentation, is added to wines as a stabilizer to prevent
further fermentation. It is used in two instances. First, to
absolutely guarantee an end of fermentation in wines that are
bottled young. Second, to stop fermentation in wines that are
intentionally sweet and the only thing inhibiting the yeast is
the high alcohol content.
The positive is that potassium sorbate works well, is generally
accepted as safe, and will give you good insurance against
exploding bottles. It is seldom noticeable at all when used for
young wines and white wines. The downside is that it can
develop off-smells in some wines over a period of years. So if
you are making a wine that you plan to keep for many years,
rather than using potassium sorbate I would recommend bulk
aging it for at least a year in a secondary fermenter to assure
the end of fermentation prior to bottling.
Another method of ending fermentation is to add
supplemental alcohol to the wine in the form of brandy
(which is distilled from wine). This process is called
fortification. Raising the alcohol level in the wine above the
alcohol tolerance of the yeast (usually 20%) assures its
dormancy. Fortification is used in the manufacture of port
wines. Port wines are typically sweet and dark, though some
dry and white ports exist. These sweet wines were stabilized
for shipping purposes by racking them into a secondary
fermenter that already contained enough brandy (about ΒΌ of
the volume of the wine) to raise the alcohol level to 18% to
