                   PICKLES AND FERMENTED PRODUCT SAFETY



     The acidity (pH) of a food is of great significance in
determining the type of processing required for safe preservation
of a food.  In the case of pickled products, the foods preserved
are often low-acid foods (cucumbers, zucchini), but their acidity
is adjusted to bring the pH into the high-acid range so that may
be safely preserved using boiling water bath processing.  

     The most commonly used acid for pickling is vinegar, however
some pickle products are produced by encouraging the growth of
microorganisms which produce lactic acid from the
naturally-occurring carbohydrates in fruits and vegetables.  The
lactic acid selects for another group of microorganisms which
produce acetic acid that gives pickle products their flavor and
helps to lower the pH into the range where these vegetables can
be safely water bath canned.  

     The acidity of pickling solutions needs to be maintained
below  pH 4.5 if water bath canning is to be used.  For this
reason, the amount and strength of the vinegar is critical.

I.   Types of Pickles

     A.   Brined or fermented:  Depends on selection of natural
          microorganisms which will produce acid.  Selection is
          accomplished by using salt to inhibit unwanted
          microbes.  Fermentation is usually for 3 weeks or more. 
          Color changes from bright green to olive or yellow
          green and white interior becomes translucent. 
          Examples: sour pickles, sauerkraut.

     B.   Refrigerator dills: are fermented for one week.

     C.   Fresh-pack or quick-process pickles:  Cured for several
          hours or  combined immediately with hot vinegar, spices 
          and seasonings.  Examples: pickled beets, bread and
          butter pickles.  

     D.   Fruit pickles:  Whole or sliced fruit simmered in a
          spicy, sweet-sour syrup.  Examples: spiced peaches,
          crabapples.

     E.   Relishes: Made from chopped fruits or vegetables which
          are cooked to desired consistency in a spicy vinegar
          solution.  Examples: horseradish, corn relish.

     F.   Pasteurized Pickles:  Prepared pickles are placed in a
          canner half-filled with warm (120-140 F) water.  Add
          hot water to 1" over jar lids.  The water is then
          heated to 180-185 F and maintained there  or 30
          minutes.  Temperatures over 185 F may cause softening
          of pickles.  

     USE THIS PROCEDURE ONLY WHEN THE USDA CANNING GUIDELINE
RECIPES ARE USED.


II.  Ingredients

     A.  Vegetables or fruits for pickling

          1.   Fruits and vegetables should be ripe but firm, and
               in good condition with no evidence of microbial or
               insect damage.  
          2.   Cucumbers should have a 1/16" slice removed and
               discarded from the blossom end.
          3.   Use unwaxed cucumbers for pickling so brine will
               penetrate.
          4.   Discard any cucumbers which "float"--they can make
               hollow pickles (use for relish).
          5.   Prepare fruits and vegetables within 24 h of
               harvest.
          6.   Cucumbers: need 14 lb for 7 quart canner load, 9
               lb per 9 pint canner load.  One bushel weighs 48
               lb and yields 16-24 quarts (2 lb / quart).  Use 1
               1/2" for gherkins and 4" for dills.  

     B.  Vinegar

          1.   Vinegar needs to be of sufficient strength to
               assure that low-acid vegetables will be
               appropriately acid.  The vinegar should            
               be 5 to 6% acetic acid (50 to 60 grain), and
               should not be  diluted except according to an
               approved recipe. 
          2.   White vinegar is preferred with light colored
               fruits or vegetables.  
          3.   Do not use homemade vinegar--there is no way to
               know the strength (% acetic acid).

     C.  Salt

          1.   Canning or pickling salt should be used--it
               contains no iodine (which can cause darkening) or
               anti-caking ingredients (sodium silicate or
               tricalcium phosphate) (which cause cloudiness of   
               the brine).  
          2.   Salt inhibits certain kinds of microorganisms and
               in fermented pickle products, it is required to
               prevent growth of spoilage and pathogenic
               microorganisms.  Salt also draws water out of   
               the cells making the pickled product more firm. 
               Too much salt will cause shriveling.
          3.   Do not use "sour salt"--it is citric acid and does
               not have the same inhibitory effect on microbes.
          4.   Do not use reduced-sodium salt in fermented pickle
               recipes.  Reduced sodium pickles can be made using
               quick pickle recipes given in the USDA Canning
               Guidelines.  Fresh pack pickles, acidified with
               vinegar can be prepared with little salt but the
               flavor and texture will be affected.  
          5.   Salt concentration in brined, fermented products
               must not be reduced for safety.  Do not try to
               make sauerkraut or fermented pickles by cutting
               down on the salt.

     D.  Sugar
               Either white or brown granulated sugar can be
               used.

     E.  Spices
          1.   Use fresh, whole spices in cheesecloth bag.
          2.   Powdered spices cause darkening and clouding.

     F.  Hard Water
          1.   Hard water minerals may interfere with acid
               formation and curing in fermented pickles.  In
               addition, hard water may have a pH of 8.0 or
               higher.
          2.   Softening hard water: boil water for 15 minutes
               then allow to stand for 24 hours.  Skim off any
               scum that appears.  Pour out of container so
               sediment is not disturbed.

     G.  "Crisping Agents"

          These products are not recommended as they may result
          in a product with a pH which is unsafe.

          1.   Lime (calcium hydroxide) which is sold as
               "slakelime", "hydrated lime", "builders lime", or
               "household lime".  When called for in a recipe, it
               is added to the brine before pickles are soaked.  
               When used, lime is added for 12-24 hours of
               soaking.  It must be removed from pickles by
               soaking (1 hour) and rinsing three times in fresh
               water in order to make the pickles safe.  The
               component of calcium hydroxide which firms up the
               pickles is the calcium--it cross-links the pectins
               making them insoluble.

               DO NOT USE:  agricultural lime, burnt lime, quick
               lime--these are not food grade products and are
               unsafe.

          2.   Alum (aluminum and potassium sulfates):  Use no
               more than 1/4 tsp of alum per quart of pickling
               solution.  Excess will cause bitterness.  Alum may
               be safely used--it does not improve the firmness
               of quick-process pickles.

          3.   Grape leaves: contain substances which inhibit
               enzymes that make pickles soft.  Blossom removal
               takes care of this problem.

          4.   Hot process: pickle firmness may be improved by
               processing the pickles for 30 minutes in water
               maintained at 180 F.  Water must not fall below
               180 F--prevents spoilage (pasteurization). 



Prepared by Susan Brewer
Foods and Nutrition Specialist
Revised, 1992                                                     
EHE-696

