When the wine is clear and all fermentation has stopped, siphon it into wine bottles and cork the bottles securely. Leave bottles upright for 3-5 days and then store them on their side at 55 degrees Fahrenheit for six months (white wine) to a year (red wine) before sampling. If not up to expectations, allow to age another year or more. While this is the essence of this step, there is actually a bit more to it.
It is assumed the wine will fall clear on its own within six months and perhaps another three rackings. Almost all wines will, but some may need help. Help means either cold settling or fining. It does not mean filtering, as only clear wines should be filtered. Filtering a cloudy or hazy wine will almost always clog the filters prematurely and could burn out a filter's pump.
Generally, fining agents work because they possess one charge (positive or negative) and the cloudiness is caused by something that possesses the opposite charge. Opposites attract, creating larger (and heavier) particulates, which fall into the lees. If you use the wrong fining agent, it will repel the particulate and serve no purpose. Indeed, it could exacerbate the problem.
The best -- meaning the most useful -- general fining agents are (in my opinion) Bentonite, Kieselsol, Chitosan, and Gelatin. The first two are negatively charged particles that are useful in removing proteins and some metallic compounds. The latter two are positively charged and useful in removing tannin, phenols, anthrocyanins, yeast cells, and bacteria -- all of which are negatively charged. Casein and Sparkolloid are also useful and fairly common finings. Both are positively charged agents. There are at least a couple of products out there that are two-part clarifiers. They contain both positive and negative charged finings, so if you really aren't sure what is causing the problem and you've tried pectic enzyme without success, these products will usually work. In fact, I've never had one not work for me. The one I've used most often is a product is called Super Kleer K-C, a liquid, whose fining agents are Kieselsol and Chitosan (the "K-C" in the name). One 150-ml dose will treat 6 gallons of wine. Ten days later you rack the wine and, if desired, filter it at that time.
After the wine is clear, it must be stable before being bottled. Stable means all fermentation has stopped for good. An unstable wine can resume fermentation in the bottle and lead to disaster -- a popped cork or exploded bottle.
Any wine that is absolutely bone dry will stabilize itself within a few days to weeks, as no food remains to keep the yeast alive. For bone dry wines (specific gravity of 0.990 or lower), allow them to sit for 30 days before bottling.
If the wine is not bone dry, it may be cold stabilized at 30-32 degrees F, for 3-4 weeks. This will kill all popular strains of wine yeast. If you cannot reliably reduce your wine to this temperature range for an extended period, you can chemically stabilize it.
Potassium sorbate, sold as a chemical or behind a product name such as Sorbistat K, is a commercial wine stabilizer that should be used in conjunction with Campden or its active ingredient, potassium metabisulfite. In other words, it works better with sulfites present than without, and it works better than sulfites alone. Potassium sorbate disrupts the reproductive cycle of yeast. Yeasts present are unable to reproduce and their population slowly diminishes through attrition.
Potassium sorbate is added in the amount of 1/2 teaspoon per gallon of wine. Sorbic acid results and stabilizes the wine. Usually the crushed Campden and potassium sorbate are dissolved in a cup or two of the wine to be stabilized and stirred thoroughly. Allow the stirred wine to sit a few moments and look for small white lumps of undissolved powder. If present, continue stirring until the wine is clear without any undissolved lumps. This is then added to the larger batch and stirred in well with a sanitized glass rod or wooden dowel.
Once a wine is stabilized it can be sweetened if desired. Sweetening a wine that hasn't been stabilized is asking for trouble. Sweeten the wine any way you desire, but the most assured way of doing it is to make a simple syrup from two parts sugar to one part water and stir until the sugar is completely dissolved and the liquid is clear. It helps to use boiling water for making the syrup. Then add the syrup to the wine and stir well to integrate it. I add in stages, stir well, and taste -- 1/2 cup, then 1/4 cup, then however more is needed to achieve the taste I desire. Do not add sugar directly to a finished wine. More than likely it contains a great deal of absorbed carbon dioxide, as explained in the paragraphs immediately following, and adding sugar crystals will cause it to erupt like a volcano with foam. After sweetening, reattach the airlock and let the wine sit another 3-4 weeks to be sure it doesn't start refermenting.
It is not uncommon for wine to absorb carbon dioxide, the gas created as a by-product of fermentation. This especially tends to occur when fermentation slows to the point that bubbles escape the airlock at a rate slower than one bubble every 15 minutes. The positive pressure of CO2 in the headspace between the wine and the airlock bears equally on the wine and the liquid inside the airlock. Some of that CO2 is simply absorbed into the wine. The result is a wine that fizzes when poured. It may not fizz as much as a sparkling wine, but it greatly detracts from a wine that is supposed to be a still (nonsparkling) wine.
There are several ways to release this gas and return the wine to a true still wine. The simplest way is to simply stir the wine with a wooden dowel or a plastic rod. Stir the wine vigorously for about a minute and then replace the airlock and let the wine settle down for 30-45 minutes. Then repeat the procedure several times until the wine stops giving up CO2 gas. I use a plastic rod used to pull curtains closed. I heated one end of the rod in boiling water for a few minutes, layed the heated end on a wooden cutting board, and gently tapped it with a wooden mallet to flatten the end of it into a narrow "paddle" shape. I sanitize it and then put the paddle end into the carboy and attach the other end to an electric drill. This is undoubtedly safer than using a wooden dowel because the plastic cannot absorb bacteria or mold the way the wooden dowel can.
All wines benefit from bulk aging before bottling. The length of time a wine is bulk aged is up to you, but whites generally should be aged at least six months, Low acid, low tannin reds should be aged for 9-12 months. High acid, high tannin wines should be aged considerably longer. Aging is usually done under airlock, but long aging can be done in sealed carboys, the seal being provided by a solid bung or tapered cork.
You may bottle the wine with simple racking tubing. I insert the tubing into the bottle at the depth I wish the wine to rise to (1-3/4 inches if using 1-1/2-inch corks, 2 inches if using 1-3/4-inch corks. When the wine rises to that height, I simply lift the bottle above the height of the wine in the secondary. Flow stops and wine above the end of the tubing is siphoned back into the carboy. There are also valves that can be fitted to the end of the tubing and used to cut off wine flow at the appropriate time. Finally, there are bottling wands that fit into the end of the tubing and are inserted into the bottle. They contain a spring-loaded valve that is opened when the tip is pressed against the bottom of the bottle. When the bottle is filled to the appropriate height, the wind is merely lifted and flow stops. The choice is yours. Each method requires a few attempts to become expert at, but there is no rocket science involved and anyone can quickly master either of the methods.
Newly bottled wine should be stood upright for three days. During this period it is labeled and a decorative heat-shrink capsule may be fitted over the corked neck. After three days, it is stored on its side so the cork is fully in contact with the wine.
Bottled wine should be allowed to age in the bottle at least two and preferably three months to recover from the agitation bottling imposes upon it (so-called "bottle sickness" or "bottling shock") and to develop a bottle bouquet.
More detailed instructions and advice on each of the steps outlined above can be found in the section of this website called "Advanced Winemaking Basics," reachable in the navigation menu below. One should especially note the subsections "Winemaking Problems" and "Finishing Your Wine."