IF ILTRI TANGENZIALI CFK DELLA TOFFOLA by VK49fI6

VIEWS: 7 PAGES: 6

									Thermal Treatment of Wine Grapes:

       Laccase Denaturation
               and
      Sensory Defect Removal
     Flavor 101A-Recognizing Off Flavors
                  UC Davis
             09 December 2011


                                               Rick Jones
                                    Consulting Winemaker
                                        Della Toffola USA
The Goal is Simple:
 Permanently deactivate laccase by
  heat denaturation of the protein.
 But there’s a catch…you must heat to
  very high temperature (greater than
  150 F) RAPIDLY or you can make
  things worse!
 Why?
Enzyme Activity Increases with
Temperature
                                 Effect of Temperature

                      250

                      200
      Rel. Activity




                      150

                      100

                       50

                        0
                            10   20   30      40    50    60        70   80   90
                                           Temperature (degree C)
       3 General Methods
1.   Classic Thermovinification
           Heat to 140 F, hold for 2-12 hours, chill, press and ferment
                     + good color
                     + inexpensive capital requirements
                     - poor tannin extraction
                     - energy intensive (need to heat and cool)
                     - heating usually not fast enough for denaturation
2.   Hot Maceration (MPC)
           Heat to 140 F, hold for 2-24 hours, chill, ferment on skins
                     + For higher quality grapes
                     - On Skins ferment can cause reintroduction of moldy character
3.   ThermoFlash or Flash Detente
           Heat quickly to 180F followed by immediate cooling in a vacuum chamber
                     + good color AND tannin extraction
                     + ability to press off a balanced must immediately to discard
                        moldy skins
                     + complete laccase denaturation
                     + entrainment of moldy character in flash water that can be
                        discarded
                     - expensive
The COOLER UNIT

								
To top