Michigan
State University Extension
Preserving
Food Safely - 01600598
10/13/97
General Information
There are two classifications of pickles, fermented and
fresh pack. Fermented pickles (also called brined pickles)
are prepared by soaking cucumbers in brine for several
weeks. During this period lactic acid bacteria, which are
salt tolerant, produce lactic acid from natural sugars in
cucumbers. Lactic acid not only preserves the pickles but
also imparts a characteristic flavor. Most spoilage
microorganisms cannot tolerate the saltiness of the brine
and die. Yeasts, which require air, grow as a scum on the
surface of brine. This scum of yeasts should be removed
daily because they destroy the lactic acid produced by
bacterial fermentation and produce enzymes which break down
pectic substances in the pickles, making them soft and
mushy.
Fresh-pack pickles are prepared by soaking cucumbers in
brine for a few hours or overnight, then draining them and
covering them with a boiling hot pickling solution
containing vinegar and spices. They are not fermented. The
vinegar, which should be 5 percent acetic acid, acts as the
preservative. The short brining procedure serves two
purposes. First, it removes bitter juices present in some
cucumbers and enhance the uptake of pickling solution,
resulting in a firmer product. Too strong a brine shrivels
the cucumbers. Too weak a brine removes too little water,
thus making possible undue dilution of the pickling solution
with resulting spoilage.
Processing in a boiling-water canner is recommended for
both fermented and fresh-pack pickles.