Crush Brix AdjustmentWhy adjust brix?
Brix is a measure of soluble solids, and in grape juice that is mostly sugar. Our friends the yeast convert this sugar into alcohol, and the resulting alcohol plays an important role in the character and balance of our wine.
Depending on where you live, grapes are probably ripening with sugars higher than you want, or lower than you want (and rarely just where you want). In these cases it's important to correct the sugar content of the juice or must so that you end up with an alcohol content that will fit your wine stylistically.
In warm climates that means adding water to the must to reduce the sugar content, and in cold climates that means adding sugar to the must to increase the sugar content. Note that you can add either granular sugar or grape juice concentrate to achieve this goal, and depending on where you live one of these options is probably illegal (there, you've been warned.)
If you're dealing with a variety of grapes that tends to raisin (such as Zinfandel) or a vintage with a higher percentage of raisins, you should wait 2-3 days for the must to 'soak up' the sugar out of these raisins before correcting the Brix.