On food and cooking the science and lore of the kitchen ( PDFDrive ) 1031

Guidelines for Working with Sourdoughs
The key to successful baking with sourdough
starters is to limit bacterial growth and
acidification, and encourage a healthy yeast
population. In general, this means keeping
sourdough starters relatively cool, and
“refreshing” them frequently by adding new
flourandwaterandaeratingthemvigorously.
Herearerulesofthumbtokeepinmind.
FrozenandPar-bakedDoughsand
Breads
Bread dough can be frozen, thawed, and
bakedintobread,butfreezingkillsalarge
proportionoftheyeastcells,whichmeans
lessleaveningpower,aslowerrise,andthe
spread of yeast chemicals that weaken
gluten. Sweet rich doughs turn out to
freezethebest.
Thebeststageatwhichtofreezebread
dough is after the dough has risen and
baked for 70 to 80% of its usual baking


time.Thisfrozen“par-baked”breadcanbe
thawed and finished with just a few
minutesinahotoven.Yeastsurvivalisno
longer important, because the yeast cells
have done their leavening and are killed
duringtheinitialbake.
Bothyeastsandbacteriagrowfastestin
liquidstarters,whichallowthemicrobes

easieraccesstonutrients;inasemisolid
doughtheygrowmoreslowlyandrequireless
frequentattention.Becausegrowingmicrobes
consumenutrientsrapidly,andproduceacid
andothergrowth-inhibitingsubstances,
startersneedtobedividedandrefreshed
frequently,twoormoretimesperday.Adding
newwaterandflourdilutestheaccumulated
acidsandothergrowthinhibitors,and
providesafreshsupplyoffood.Aeratingthe
starter—whiskingaliquidone,orkneadinga
doughyone—suppliestheoxygenthatyeasts
requiretobuildcellmembranesfornewcells.
Themorefrequentlythestarterisdividedand