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gelatinconcentration.
Bothstronglyacidingredientsandthe
tanninsinteaorredwinecancloudajelly,
theacidsbyprecipitatingproteinsinameator
fishstockintotinyparticles,andthetannins
bybindingtoandprecipitatingthegelatin
moleculesthemselves.Theseingredientsare
bestcookedbrieflywiththegelatinsolution
sothatitcanbestrainedorclarifiedbefore
setting.
Anumberoffruits—papaya,pineapple,
melons,andkiwiamongthem—contain
protein-digestingenzymesthatbreakgelatin
chainsintoshortpiecesandthuspreventthem
fromsettingintoagelatall.Theyandtheir
juicescanbemadeintoajellyonlyaftera
briefcookingtoinactivatetheenzymes.
Cooling Temperatures The temperature at
which the gel forms and ages affects its
texture. When “snap-chilled” in the
refrigerator, the gelatin molecules are
immobilized in place and bond to each other
quickly and randomly, so the bonds and the
structure of the network are relatively weak.
When allowed to set slowly at room
temperature, the gelatin molecules have time
to move around and form more regular helix
junctions, so once it forms, the network is
more firm and stable. In practice, jellies