On food and cooking the science and lore of the kitchen ( PDFDrive ) 703

production goes to make wine; of the rest,
about two-thirds are eaten fresh and a third
are made into raisins. There are many
thousands of grape varieties. Most wine
varietiesoriginatedinEurope,whilevarieties
for eating fresh or making into raisins can
oftenbetracedbacktowesternAsianparents.
Winegrapescomeinrelativelysmallclusters
andareacidicenoughtohelpcontroltheyeast
fermentation; table grapes come in large
clustersandarelesstart;raisinvarietieshave
a thin skin, high sugar content, and loose
cluster structure to facilitate drying. The
commonest table and raisin grape in the
United States, the Thompson seedless or
sultana, is a variant of an ancient Middle
Eastern all-purpose variety, the Kishmish.
Table grapes are quite diverse. They may be
seedy or seedless, deep purple with
anthocyanins or pale yellow; their sugar
content may range from 14 to 25%, their
acidity from 0.4 to 1.2%. They may have a


fairly neutral, green aroma (Thompson
seedless), or be flowery and citrusy from
terpenes(muscat),ormuskywithanthranilate
andotheresters(ConcordandotherAmerican
varieties). Most commercial varieties today
havebeenbredtobeseedless,crisp,tart,and
sweet, with a long storage life. Thompson

seedless grapes picked in the cool of the
morningandtreatedwithantimicrobialsulfur
dioxidecanbeheldforaslongastwomonths
at32ºF/0ºC.
Raisins Grapes are easily preserved by
sundrying to make raisins. In the United
States this is usually done by laying the
grapesonpaperbetweenrowsinthevineyard
for about three weeks. Raisins are naturally
brownandhavecaramelflavornotesduetoa
combination of browning-enzyme oxidation
of phenolic compounds and direct browning
reactionsbetweensugarsandaminoacids(pp.
269, 778). Both of these processes are