Monday, October 27, 2008

Temperature Control with the Winepod


The controller on the Winepod is probably the most important feature, even more important than the brix meter (since brix can be measured with the hydrometer). Fermentation at a steady temperature is critical to winemaking because it reduces the variation in fermentation byproducts (no banana odors please!!).

The Winepod has an automatic temperature controller. It requires the user to enter lower and upper set point temperatures. The controller turns on the heater when the must drops more than 1 degree below the lower set point and turns on the cooler if it reaches 1 degree above the upper set point. I keep the Winepod in the basement where the temperature is between 54 and 57 degrees F. I originally set the set points at 62 and 63F. Bad idea. This caused the Winepod to constantly switch between running the heater and cooler. The heater would raise the temperature at the sensor so rapidly that it would overshoot 64F and the cooler would turn on. The cooler would overshoot in its cooling effect continuing the cycle. I set the lower set point at 61F and the upper set point to 65F. This seemed to produce a fairly consistent temperature in the low 60s. As the fermentation continued, the must began to reach more or less steady state around 60F, just above the point where the heater would turn on.

Since I actually want a steady state temperature closer to 61F, I reset the lower set point to 62. When the heater turns on at 60.9 degrees F, the must is heated until the liquid immediately surrounding the temperature sensor reaches 64F. Once the heater shuts off, the sensor temperature reading drops rapidly for above 5 minutes as the heat disperses throughout the entire volume of must. After the quick temperature drop from 64 to 61.3F, the temperature holds near 61F for about 25 minutes before the heater comes on again.

The must is starting to smell of alcohol, but has a flowery smell.

Brix is at 7.42/Temperature 61.1F at 2AM on October 28, 2008.

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