Agriculture Reference
In-Depth Information
(buttery) flavors. Both statements are true. However, if you
are scrupulous in your sanitation, acetification is not likely to
happen and some wines could benefit from any diacetyl
developed. That having been said, if you are concerned about
this, you can substitute tartaric acid for citric acid, and by
doing this you will increase the grape flavors in your wine.
Pectins
Pectins are long chains of carbohydrates composed of various
sugars that form the cell walls of the fruits used to make wine.
Pectins are responsible for turning the juices of some fruits
into jelly. European grapes contain enough pectic
enzyme—an enzyme that destroys pectin—to destroy that
pectin so you end up with a clear fluid wine rather than a
semi-solid gelatinous mass. Other fruits don't usually have
enough of this enzyme naturally, which makes them excellent
for making jelly but suboptimal for wine.
Pectic enzyme purchased from the winemaking store is used
in small amounts to supplement the natural pectic enzymes in
the must. Over time, this degrades the pectin and thereby
either makes its sugars available for fermentation or
precipitates the leavings into the bottom of the fermenter so
they are left behind at the next racking. Therefore, pectic
enzyme helps to produce clear wines.
You may recall that one reason most fruits and vegetables are
blanched before freezing or dehydrating is that the high
temperature of blanching inactivates the enzymes that cause
the produce to degrade over time. The same will occur with
pectic enzyme, so pectic enzyme should only be added to a
