During fermentation the temperature is monitored for multiple reasons. From a biological standpoint the yeast become sluggish at very cold temperatures and can be killed at higher temperatures. From sensory standpoint, high temperatures in the fermentation process can lead to the production of hydrogen sulfide (rotten egg smell) by certain strains of yeast and can produce a cooked flavor in the finished product.
Large producers of wine will use a cooling system to remove the heat produced by the fermentation process. These cooling systems include a jacketed fermentation tanks that are cooled by glycol or ammonia.
There is much debate about the ideal fermentation temperatures. According to Wyeast, a yeast manufacturer, white wines are fermented at colder temperatures (45-60 oF/7-15 oC) and red wines are fermented at warmer temperatures (70-85 oF/20-30 oC). It is found that at colder temperature preserve fruity aromatic compounds that are characteristic in white wines while higher temperatures provide for better tannin and color extraction, which are good for red wines.
Temperature is also important in the conditioning and storage of wine prior to bottling. Red wines are conditioned at 68 oF/20 oC while white wines at 60 oF/15 oC.
A selection of thermometers available to measure temperature in wine. These include portables based on thermistor and thermocouple sensors. Also available are testers, monitors, and data loggers.
Below are the most common thermometers for measuring temperature during the wine making process.
For the Winemaker we offer a variety of portable thermometers including versions that use thermocouple or thermistor probes. Models include meters that either have a fixed probe attached or ones that allow different probes to be used.
Portable Thermistor Thermometers
Portable thermistor thermometers offer a high accuracy temperature measurement within a -50.0 to 150.0 oC range. Thermistor thermometers include versions that can be calibrated in a ice bath, that have a backlit LCD, and with CAL Check to determine if internal electronics are working correctly.
Portable Thermocouple Thermometers
Portable thermocouple thermometers offer a wider measurement range and faster response time that thermistor based thermometers. Typically, a K-Type thermocouple can measure up to 1350 oC/2462 oF. Thermocouple thermometers include versions that can be calibrated in a ice bath, that have a backlit LCD, and with CAL Check to determine if internal electronics are working correctly.
The pocket thermometers or testers available are precision instruments. The accuracy is typically ±0.3 °°For better and many of the meters offer CAL Check technology to check for drift in the internal electronics that can lead to erroneous measurements.
multiple versions are available including a meter with a weighted probe that is designed for vats.
Monitors & Data Loggers
Data loggers are available to track and monitor storage temperatures. Also available is a magnetic backed thermometer that is sued to monitor the temperatures of refrigerators.
Many different style temperature probes are available These include both thermistor and thermocouple versions.
Accessories in this category include test keys for thermistor based thermometers along with shockproof rubber boots. These boots give additional protection from accidental drops and provide for a more tactile feel when holding the meter.