were preserved for some weeks in seawater or
a 5 to 10% brine while they were shipped
from Asia and the Middle East to Europe; now
they’re brined to develop flavor. Yeasts grow
on the peel and produce alcohol, which then
supports acetic acid bacteria. The result is the
production of volatile esters that deepen the
aroma of the peel. The preserved lemons of
Morocco and other north African countries
have a similar character; they’re made by
packing cut lemons with salt and fermenting
for days to weeks.
Sugar Preserves
Another venerable technique for preserving
fruits is to boost their sugar content. Like salt,
sugar makes the fruit inhospitable to
microbes: it dissolves, binds up water
molecules, and draws moisture out of living
cells, thus crippling them. Sugar molecules
are quite heavy compared to the sodium and