Red Wine Fermentation

The must is fermented in a wide topped container 1/2 to 2/3 full, preferably with a lid to reduce contact with fruit flies.  Sugar content should be adjusted to 22 to 24°Brix if necessary.  Sugar addition can be delayed until the must is fermenting and forming a cap of skins on top.  When the cap forms, the actual amount of liquid can be more closely estimated.  A formula can be used to calculate sugar addition rates.  Addition of a yeast nutrient (eg. diammonium phosphate or DAP) is optional.  Prepare yeast the same as for white wine, but note that the red must should be at around room temperature (around 70°F) so there is less danger of temperature shock to the yeast.  Fermentation of the red must is best at temperatures in the range of 77 to 86°F.  Temperature over 90°F should be avoided.  As long as the room where the fermentor is located stays in the 70's, the fermentation should not get too hot (assuming the container is not too large).  As the must ferments, skins and seeds will rise to the top.  To keep the grape skins in contact with the liquid for color extraction and to release trapped heat, the cap should be broken up and  pushed down below the level of the liquid in the container at least twice daily (see photo).  The fermentation should take from 5 to 7 days.  When the cap no longer forms and the skins and seeds sink to the bottom of the container the fermentation is over.  The skins can be pressed off prior to the end of fermentation (3 to 5 days and 0 to 5°Brix) to produce a red wine that requires less aging.