Chard at 18 Brix and 77 degrees

We checked the Chardonnay over lunch and it is fermenting violently. Brix are down to 18 and the juice/must is at 77 degrees, which is warmer than we would like--the wood barrel is insulating the juice from the cool air in the cave.  I think we should have tried to cool the juice before we started fermentation.  We were trying for a 60-65 degree fermentation and the yeast says it works best from 56 to 72 degrees. We did the second Fermaid-K nutrient addition of about 25 grams and stirred the must

 

Any ideas on how to cool the juice down? The only thought I have is to pull a couple gallons of juice out and put it into the freezer to get it good and cold and then pour it back in.  Other ideas? 

 

Troy