On food and cooking the science and lore of the kitchen ( PDFDrive ) 1412

Oncethefoamisofthedesiredthickness,the
restofthebeercanbepouredingentlyalong
the side of the glass, avoiding aeration and
nucleation of new bubbles. The glass itself
shouldbecleanofanyresiduesofoilorsoap,
which interfere with foaming. (These
molecules have water-avoiding ends that pull
the similar ends of the bubble-stabilizing
proteins out of the bubbles.) By the same
token, if a newly poured beer threatens to
foamover,itcanoftenbestoppedinitstracks
bytouchingtherimwithafingerorlip,which
carrytracesofoil.
KindsandQualitiesofBeer

Beersareawonderfullydiversegroupof
drinks,andagoodbeercanbeamouth-filling
experience,onethatrewardsslowsavoring.
Thereareseveralqualitiesworthappreciating:
Color,whichcanrangefrompaleyellow


toimpenetrablebrown-black,andcomes
fromthekindsofmaltused
Body,orweightinessinthemouth,which
comesfromthelongremnantsofstarch
moleculesinthemalt
Astringency,frommaltphenolic
compounds
Pricklyfreshness,fromdissolvedcarbon
dioxide

Taste,whichmayincludesaltinessfrom
thewater,sweetnessfromunfermented
maltsugars,acidityfromroastedmalt
andfromfermentationmicrobes,
bitternessfromhopsandfromdarkroastedmalts,savorinessfrommalt
aminoacids
Aroma,fromwoody,floral,citrusyhops;
malty,caramel,andevensmokymalt;
andfromtheyeastsandothermicrobes,
whichcanproducenotesthatseemfruity
(apple,pear,banana,citrus),flowery
(rose),buttery,spicy(clove),andeven