Page 18 - Grapevine SeptOct 2021
P. 18

In The Winery


               gallon it will cost a winery roughly $2.55, in distilled  death of the microorganism.
               water costs, to achieve sterility before bottling.
                                                                                    High pH Cleaners
                             Physical Cleanliness
                                                                      High pH cleaners will give the water a slick feel-
                 While pursuing a Food Science Degree, one will     ing.  This is the action of the lowering of the surface
               study sanitation in great depth.  From this we learn   tension making the water seem soapy.  Common
               that a physically dirty surface cannot be sanitized   examples of high ph cleaners are:  TSP (tri-sodium
               with sanitizing agents.  To understand this, we must  phosphate); soda ash (sodium carbonate); NaOH
               understand that a sanitizer reacts on the surface    (sodium hydroxide).  High pH cleaners will also kill
               with whatever it comes into contact.                 certain bacteria by disrupting the bacteria’s cell
                                                                    wall.  Once the cell wall is disrupted the bacteria
                 Let’s assume one has cleaned a surface but left    may die.  As mentioned earlier, if using a high pH
               behind some dirt that has remained on the surface.   cleaner always rinse the same surfaces that came
               While one may achieve a brief moment of cleanli-     in contact with the high pH cleaner with a low pH
               ness using a sanitizing agent, it is not properly pre-  cleaner.  This will prevent any of the unwanted
               pared to receive a grape juice or wine product.  The  cleaning agents from being introduced into the
               sanitized microbes will slough off the surface of the  wine.  A common low pH rinse for this application
               viable bacteria and expose living bacteria ready to   is a solution of citric acid and water.  Be sure to
               grow!  For this reason we want to remove all physi-  rinse the citric from the same surfaces with just
               cal dirt before using a sanitizer.                   water after using that formulation.
                                                                    Low pH cleaner
                 It is also for this reason that stainless steel has
               become such a large part of our storage vessels for     A low ph cleaner will also penetrate the cell wall
               wineries.  Stainless steel is easily cleaned physically   of some bacteria causing them to die.  This action
               and it holds up to chemical cleaners.  For this rea-  happens at approximately a pH of 2.6.  Very few
               son – please clean your tanks and enjoy the beau-    low pH cleaners are used in the wine industry
               ties of stainless steel.                             except to rinse away the high pH cleaner, usual-
                                                                    ly with citric acid as mentioned in the paragraph
                            Chemical Cleanliness                    above.  Larger wineries may use a phosphoric acid
                                                                    solution for its low pH microbe killing power.
                 Many chemicals come to mind when we want to
               clean.  Be careful to select the proper chemicals.                         Ozone

                 Do not use soaps or detergents.  Although they       Ozone, a strong oxidizer, has strong killing power
               are great surfactants [lowers the surface tension of   when used properly.  Many vintners find it helpful
               water], they are very difficult to rinse from surfaces  when using it with barrels that have had a micro-
               due to how they lower the surface tension of the     bial infection.  Most agree that once a barrel has a
               water and often residuals remain.  These residu-     spoilage microbe inside, it is difficult to completely
               als can cause problems in wines and their flavors.    remove or kill the microbes beneath the surface of
               Below are the categories of chemicals that are       the wood cells.  Ozone is very effective in killing all
               largely used in the wine business in no particular   microbes when it contacts the microbe.  Research
               order.                                               and be very careful with Ozone use safety wise.

                                                                                     Sulfur Dioxide
                          Quaternary Ammonium
                                                                      Commonly used in the wine cellar as an every-
                 Quaternary Ammonium is used mostly to clean        day tool, winemakers must realize this chemical
               winery floors and walls although sometimes it is     does little to sterilize and is limited in its sanitizing
               used to clean tanks, hoses and equipment.  Modern  power.  It should always be used in combination
               formulations have made these noncorrosive and        with citric acid, as a cleaning agent, since the lower
               heat stable while attacking a very broad range of    ph water will increase the effectiveness of the sul-
               microbes via disrupting their cell wall resulting in   fur dioxide thereby releasing more sulfur dioxide in

               Page 16                       The Grapevine • September - October 2021                          877-892-5332





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