Simply put, the chiller operates by running fluid (Glycol) through a compressor that chills the fluid down to about 20 degrees F, in turn creating an icy blanket around the stainless steel tanks.
Here are a few important wine making uses for this piece of equipment:
The chiller is first used in wine making to cold settle the white juice after we crush and press white grapes during harvest. Once the juice is in the tank, the chiller is turned on, chilling the juice to 34 degrees F. This step settles out the pulp leaving clean, clear juice for fermentation. For reds, you may choose to run the chiller to cold soak the juice, which chills red juice on the skins prior to fermentation to extract more color and tannin.
The chiller is used to maintain fermentation temperatures. White wines need to ferment between 50-60 degrees F and red wines between 60-70 degrees F.
For white wine, after fermentation is complete the chiller is used for cold stabilization. This is when wine is chilled to 28 degrees F for several days to drop the tartrates in wine. The tartrates precipitate out of the wine and fall to the bottom of the tank. They look like crystals or snowflakes. They are not harmful (think cream of tarter), they just don't look good so most winemakers remove them during production.
Finally, the chiller is used to maintain the finished wine at the proper temperature. We keep most of our wines between 55-65 degrees F.
