On food and cooking the science and lore of the kitchen ( PDFDrive ) 975

crackstheinnershellopen.Traditionally,the
ripefruitswereknockedfromthetreesand
sun-dried,andthehullpigmentsstainedthe
shell,sotheshellswereoftendyedtomake
themauniformred.Today,mostCalifornia
pistachiosarehulledbeforedrying,sothe
shellsaretheirnaturalpaletancolor.
Pistachiosareremarkableamongthenuts
forhavinggreencotyledons.Thecolorcomes
fromchlorophyll,whichremainsvividwhen
thetreesgrowinarelativelycoolclimate,for
exampleathighelevation,andwhenthenuts
areharvestedearly,severalweeksbeforefull
maturity.Pistachiosthusoffernotonlyflavor
andtexturebutacontrastingcolorinpâtés,
sausages,andothermeatdishes,andinice
creamsandsweets.Thecolorisbestretained
byroastingorotherwisecookingthekernels
atlowtemperaturesthatminimizechlorophyll
damage.
Walnuts Walnuts come from trees in the


genusJuglans, of which there are around 15
species native to southwestern Asia, eastern
Asia, and the Americas. The most widely
cultivated is the Persian or English walnut,
Juglansregia,whoseseedshavebeenenjoyed
since ancient times in western Asia and
Europe, and among tree nuts are second only
to almonds in worldwide consumption. In

many European languages, the generic term
fornutisalsothewordforwalnut.TheUnited
States, France, and Italy are the major
producers today. Walnuts have long been
pressedfortheiraromaticoil,wereoncemade
into milk in Europe and China, and came to
providetherich,flavorfulbackboneofsauces
in Persia (fesenjan), Georgia (satsivi), and
Mexico (nogado). In some countries,
immature “green” walnuts are harvested in
early summer and pickled (England), used to
flavor sweetened alcohol (Siciliannocino,
Frenchvindenoix),orpreservedinsyrup(the
MiddleEast).