Making good wines, like any other task requires a good process.
In the numerous functions of processing grapes or other materials into wines, perhaps the most fundamental is the primary fermentation. If we don't get that right, the rest of our process becomes insignificant.
Lets take a look at how to effectively manage the process of primary fermentation.
CLEAN EVERYTHING that comes in contact with your juice, must or wine.
We highly suggest you keep good records of your findings, here is a great sheet to use:
http://scottlab.com/uploads/documents/downloads/272/Fermentation%20Management%20Chart.pdf
Make sure your yeast dosage is adequate, using an amount proper for the volume of juice or must you are fermenting is vital to a healthy process.
Rehydrate your yeast properly. A healthy biomass is vital to clean uninterrupted fermentation. Use a good yeast rehydration nutrient like Go Ferm. This product will improve the vitality of the yeast enabling them to perform well under stressful conditions as the alcohol in the must increases.
It is important to use a good fermentation nutrient. These provide food for yeast and keeps them healthy, and timely measured additions are vital. Additions should be made at 1/3 sugar depletion and again at half sugar depletion.
An example would be: 24 brix, 1/3 depletion would be at 16 brix, make the first addition. At 12 brix, or half the beginning sugar level make the second addition.
Know the condition of your fruit is imperitive to the process. Nature isn't always perfect and growing seasons are what defines the quality of every vintage. Assuming your grapes are in the proper condition is a bit cavalier.
25 brix is the maximum sugar level grape vines can produce. Fruit under 25 brix, while certainly useable, isn't fully mature. Consider using an aggressive yeast strain that ferments quickly for grapes in this condition. Fruit over 25 brix is dehydrating and may be low in acid. Fully mature fruit with dark seeds will benefit from slower extended fermentations. Tannins are supple and lend themselves to improving the overall structure and depth of wines.
Temperature also plays an important role. Temperatures from 70 to 78 degrees for reds and 62 to 68 for whites can have positive effects on your wines. Monitor your temps daily, but don't stress your yeast in environments that are too warm or to cold. Remember fermentation generates heat, having a few frozen water bottles to drop in your must is helpful if you don't have any means to control temperature. Have a few back up bottles ready and switch them out as needed.
Stir or turn over your cap frequently. Keeping the yeast cells in the mix will help them from becoming buried under the lee's or the cap. Keep them suspended.
CLEAN EVERYTHING that comes into contact with your juice, must or wine.
Being proactive, monitoring progress, and simply paying attention to your primary fermentation will get you off to a great start in crafting better wine.
Don't take chances. Take charge!
