earliest sugar preserves were probably fruit
pieces immersed in syrupy honey (the Greek
termforquincespackedinhoney,melimelon,
gaveusthewordmarmalade)orintheboileddown juice of wine grapes. The first step
towardjamsandjellieswasthediscoverythat
when they were cooked together, sugar and
fruit developed a texture that neither could
achieve on its own. In the 4th centuryCE,
Palladius gave directions for cooking down
shreddedquinceinhoneyuntilitsvolumewas
reduced by half, which would have made a
stiff, opaque paste similar to today’s “fruit
cheese” (spreadable “fruit butter” is less
reduced). By the 7th century there were
recipes for what were probably clear and
delicate jellies made by boiling the juice of
quince with honey. A second important
innovation was the introduction fromAsia of
canesugar,whichunlikehoneyisnearlypure
sugar,withnomoisturethatneedsboilingoff,
and no strong flavor that competes with the


flavorofthefruit.TheArabworldwasusing
canesugarbytheMiddleAges,andbroughtit
to Europe in the 13th century, where it soon
became the preferred sweetener for fruit
preserves. However, jams and jellies didn’t
become common fare until the 19th century,
when sugar had become cheap enough to use
inlargequantities.

Pectin Gels Fruit preserves are a kind of
physical structure called agel: a mixture of
water and other molecules that is solid
because the other molecules bond together
into a continuous, sponge-like network that
trapsthewaterinmanyseparatelittlepockets.
Thekeytocreatingafruitgelispectin,long
chainsofseveralhundredsugar-likesubunits,
which seems to have been designed to help
form a highly concentrated, organized gel in
plantcellwalls(p.265).Whenfruitiscutup
andheatedneartheboil,thepectinchainsare
shakenloosefromthecellwallsanddissolve