Are there any special issues with making wine from frozen grapes?
The only one we have found is the difficulty of getting accurate measurements in very cold, previously frozen, musts. Acid (TA) readings seem particularly suspect. We have learned to be very careful about adding acid at the beginning of the fermentation. Our experience is that there is more acid in our frozen grapes than is first apparent. In 2008 we started to get some laboratory analysis of our red grapes before they were frozen. This has been very helpful, especially the results for TA and YAN (yeast available nitrogen). We usually have good data on our whites, because the settled juice comes from winery tanks and wineries have done the analysis on exactly what we are getting.
