Oxygen can be extremely unfriendly to wine. Although it is a necessary component in the wine aging process, it can also be detrimental to overall wine quality. J. Lohr Winery in San Jose, California, consistently tries to minimize the amount of oxygen exposure to their premium wines in controllable locations and times during the winemaking process. Too much oxygen can cause browning to white wines and flavor degradation in both red and white wines.
Using the YSI 550A handheld dissolved oxygen and temperature instrument, the laboratory staffff at J. Lohr can readily check the stainless steel storage tanks as well as the oak barrels to determine the amount of oxygen introduction when the wine is moved from one location to another through pumps and hoses. Preventative measures can be taken if the oxygen introduction exceeds a set limit. Fittings on tank valves, hoses, and pumps can be checked as potential sources of the oxygen introduction. Sparging the receiving vessel with nitrogen can greatly diminish the amount of oxygen introduction when the wine is transferred.