Wine making is a slow and lengthy process. If you are looking for instant gratification, there is likely little satisfaction to be had here. But the end result is very much worth it. The wine has been gently going through its secondary fermentation for the last 10 days and is now ready for stabilizing and clearing. To begin this step, the specific gravity should now be 0.996 or less, and should not have changed over two consecutive days. If it is still changing, let the wine continue to sit, checking the SG each day until it is stable.
Once stabilized, the goal is to stop any residual fermentation from occurring and move off all of the used yeast, as well as any remaining clay left in suspension. This is accomplished in two steps. We also want to remove as much of the trapped gasses from within the liquid as possible. Using the wine thief, remove about a liter of the wine from the top of the carboy. This can be stored temporarily in a clean, sterilized wine bottle. This will give provide enough room in the carboy to stir the wine well without overflowing.
Next, dissolve the packet of metabisulphite that came in the kit into a half bottle of bottled water, and add it to the carboy. The metabisulphite accomplishes two tasks, it will help to prevent any wild microorganisms from growing and it also acts as an antioxidant, protecting the color and flavor of the wine. As part of the chemical reaction it produces sulfur dioxide (SO2). This is where a drill mount paint stirrer can come in handy. Clean and sterilize the bit and then use it to mix the wine thoroughly. Mix for a minute or so and then let it rest until all the CO2 from the fermentation as well as the SO2 from the stabilizing have had a chance to subside. Then do it again, and again, and again. It is very important to remove as much trapped gas as possible. Failure to be diligent in this step will result in a wine with a carbonated mouth feel to it much like flat champagne.
Finally empty the packet of Chitosan into the carboy. Derived from oyster shells and other shellfish, this additive joins with the free floating yeast particles, that were previously suspended by the bentonite clay and once joined, all three become more dense than the surrounding wine, and as a result fall to the bottom. Stir the Chitosan in vigorously using the drill bit then top up the carboy with the wine reserved earlier and place an air lock back on top. Allow the wine to sit for another eight to ten days to give the sediment a chance to settle to the bottom.
Only one more step to go! Patience is a virtue, meanwhile enjoy a glass of some Vino!