concentrate the other ingredients. The boiling
is continued until the temperature of the mix
reaches 217–221ºF/103–105ºC (at sea level;
2ºF/1ºC lower for every 500 ft/165 m
elevation), which indicates that the sugar
concentration has reached 65% (for the
relationship between sugar content and
boiling point, see p. 680). A fresher flavor
results when this cooking is done at a gentle
simmer in a wide pot with a large surface area
for evaporation. (Industrial manufacturers
cook the water out under a vacuum at much
lower temperatures, 100–140ºF/38–60ºC, to
maintain as much fresh flavor and color as
possible.) Now supplemental acid is added
(late in the process, to avoid breaking down
the pectin chains), and the readiness of the
mix is tested by placing a drop on a cold
spoon or saucer to see whether it gels. Finally,
the mix is poured into sterilized jars. The mix
sets as it cools below about 180ºF/80ºC, but
firms most rapidly at 86ºF/30ºC and continues
barry
(Barry)
#1