Agriculture Reference
In-Depth Information
of extracting the juice is to clean and cut up the whole fruit (it
is important to leave the peels on because pectin is
concentrated near the peel) and put it in a flat-bottom pot on
the stove with added water. For soft fruits, use just enough
water to prevent scorching, but with hard fruits like pears you
might need as much as a cup of water per pound of fruit. The
fruit is cooked over medium heat until soft and then poured
through a jelly bag. If you want a crystal-clear product (which
I don't personally care about but many folks find aesthetically
important), it is important not to squeeze the jelly bag but
instead let the juice come through naturally and slowly. You
should get about one cup of juice per pound of fruit. Jelly
bags in various sizes can be purchased from cooking stores
and over the Internet. If you use a juice machine, you should
still strain the resulting juice through a jelly bag. If you can't
find jelly bags, you can use a double-layer of cheesecloth
lining a colander instead.
Once the juice has been extracted, it is combined with sugar
and other ingredients (e.g., lemon juice and/or pectin
depending on the recipe) and boiled on the stove until it
reaches a temperature of 220 degrees as measured with a
candy thermometer. The boiling point of pure water is 212
degrees, but that boiling point is raised when other substances
such as sugar are added to the water. As water evaporates and
the proportion of sugar in the water increases, the boiling
point will slowly increase. If you live in the mountains,
subtract 2 degrees for every 1,000 feet you live above sea
level. So if you live at 3,000 feet, subtract 6 degrees—so boil
the mixture only until it reaches 214 degrees. This is because
the higher you are above sea level, the more easily water will
evaporate because of lower air pressure.
