In very general terms a wine fermentation occurs when yeast consumes sugar and converts it into approximately half alcohol and half CO2 gas (carbonation) by weight. Primary fermentation is where 70 percent of the fermentation activity will occur. At Vintner's Cellar this first process takes place in the plastic buckets you see at the rear of the store.
Secondary Fermentation is when the remaining 30 percent of fermentation activity will occur. Unlike the typical four to seven days the primary fermentation takes, the secondary fermentation will usually last anywhere from two to three weeks depending on the amount of nutrient and sugars still available.
This is the step where the yeast is killed and the Co2 bubbles that have been produced by the yeast during fermentation are removed. If this is not done properly bottles of wine can literally explode or pop their corks out in the wine cellar.
The wine is filtered to remove sediment, yeast and many other undesirable materials that are suspended in the wine or that has collected at the bottom of the carboy. The nice thing about filtering is that it actually forces the wine ahead in its evolution. As wine ages, yeast and certain flavor and color compounds combine and settle out leaving sediment. Give your wine two to four weeks in the bottle to allow it to recover from "bottle shock" and 'filter shock" Your wine needs time to recover from being handled and disturbed. After this you will see the advantages of filtering, both in visual clarity and taste.