PreparationFollow the same procedure as white wines for culling out bad fruit, cleanliness and preparing a yeast starter. Hard and raisined berries are not a problem as overripe but juicy berries, which usually have an abnormally high sugar content and may have even started to sour. If there are many of these berries on the clusters, it's recommenced to discard the worst clusters or at least pick off the bad berries. They could boost the sugar level too high for a first class red wine.
Crushing and De-Stemming
Since the stems must be separated before fermentation to avoid extreme astringency in the finished wine, it is a near necessity to own or have access to a crusher-stemmer. A crusher-stemmer automatically separates the stems while it crushes. Without a crusher-stemmer, at least 90% of the stems would have to be raked out by hand after crushing and the remaining grapes stripped off. This can be done, but it becomes extremely tedious with even as little as 100 lbs.
If you don't own crusher-stemmer, try you best best to borrow or rent one for a few hours. At minimum, get a milk crate from a distributor and put together a makeshift device to separate the stems.
After the grapes are crushed and de-stemmed, the mass goes into a primary fermenter. The primary fermenter should be filled to no more than 3/4 capacity to allow room for the cap of grape skins, or chapeau, which will rise to the surface as fermentation starts.
A normal dose of potassium metabisulfite (45 ppm) should be added when crushing. Some winemakers omit meta at this stage, reasoning that red grapes have an abundance of tannin, which by itself is a good preservative. However, meta is desirable in my opinion because it kills the malolactic bacteria which might otherwise multiply and establish. There are three strains of malolactic bacteria, two of which are undesirable. Although malolactic fermentation is desirable, the better regimen is to kill all natural bacteria with meta at the crush and add a cultured ML strain later.
Most normally add pectic enzyme a few hours after crushing and sulfiting in the belief that it hastens the breakdown of the berry and extraction of color and flavors. You could add D.A.P. or a balanced yeast food now, but the yeast will make better use of it if you wait until fermentation is underway. The nutrients will diminish the chance of stuck fermentation or problems with hydrogen sulfide toward the end of fermentation.
Be sure to get an accurate titration of total acid right after the crush when the juice is clear. It picks up pigment from the skins soon after fermentation starts, making harder to read the endpoint when titrating with phenolphthalein. Total acidity should be corrected before fermentation if it is outside the range of .65-1.0% at the time of the crush.