On food and cooking the science and lore of the kitchen ( PDFDrive ) 1196

you’re starting with water as the continuous
phase.As the fat molecules are released into
thewater,they’resurroundedbywater—and
by the substances contained in the butter’s
own water droplets, which merge right into
the cooking water. The droplets contain milk
proteins and remnants of the emulsifier
membranesthatcoatedthefatglobulesinthe
original cream. And those protein and
phospholipidremnantsreassemblethemselves
ontothefatasitmeltsintothewater,coating
and protecting separate fat droplets and
forming the fat-in-water emulsion. However,
the droplet coatings in this reconstituted
cream are sparser and more fragile than the
original fat-globule membranes, and will
begintoleakfatifheatedcloseto140ºF/60ºC.
Anywater-basedsaucecanthusbe
thickenedandenrichedsimplybyswirlinga
patofbutterintoitattheend.Thisis
especiallyhandyinthelast-minutethickening
ofpanjuices,whichdon’thavethebenefitof


containingmuchgelatinoranystarch.
Incorporatingonevolumeofbutterintothree
volumesofdeglazingliquid—offtheheat,to
avoiddamagingthefragiledropletcoatings
—willproduceaconsistency(andfat
content)approximatingthatoflightcream.
Inpureesandstarch-thickenedsauces,a

smallamountofbutter(orcream)lubricates
thesolidthickenersandlendsasmoother
consistency.Becausethesesaucesarerichin
emulsion-stabilizingmoleculesandparticles,
theycanbeheatedtotheboilwithoutcausing
thereconstitutedfatdropletstoseparate.
BeurreBlanc The French saucebeurre blanc
probably evolved from the practice of
enriching cooking liquids with butter. It’s
made by preparing a flavorful reduction of
vinegar and/or wine, then whisking pieces of
butterintothereduction.Eachpieceofbutter
carriesalltheingredientsnecessaryforanew
portionofsauce,sothecookcanwhiskinone