On food and cooking the science and lore of the kitchen ( PDFDrive ) 1485

directhighheatcanshatterthem.Heatresistantformsofglassincorporateanoxide
ofboronthathastheeffectofreducing
thermalexpansionbyafactorofabout3,and
forthisreasonarelessaffectedbythermal
shock,thoughthey’restillnotimmune.
Enamelware In utensils calledenamelware,
powderedglassisfusedintoathinlayeronto
thesurfaceofironorsteelutensils.Thiswas
first done to cast iron early in the 19th
century, and today enameled metal is widely
used in the dairy, chemical, and brewing
industries, as well as on bathtubs. In kitchen
utensils, the metal diffuses the direct heat
evenly,theceramiclayeristhinenoughthatit
can expand and contract uniformly, and it
protectsthefoodfromdirectcontactwiththe
metal. Enamelware is reasonably durable,
thoughitstillrequiressomecare:theceramic
layer can be chipped or damaged by
quenchingahotpanincoldwater.


The Advantages of Poor Conductivity The
poor conductivity of ceramic materials is an
advantageifthecookneedstokeepfoodhot.
Good conductors like copper and aluminum
quickly give up heat to their surroundings,
whileceramicsretainitwell.Similarly,ovens
with ceramic (brick) walls are unparalleled
for the evenness of their heating. The walls
slowly absorb and store large quantities of

energy while the oven is heated up, and then
release it when the food is placed inside.
Modern metal ovens can’t store much heat
and so must cycle their heating elements on
and off. This causes large temperature
fluctuations, and can scorch breads and other
foodsthatarebakedathightemperatures.
Aluminum

Aluminumhasbeenusedinpotsandpansfor
barelyacentury,despitethefactthatit’sthe
mostabundantmetalintheearth’scrust.Itis