ABSTRACT

The source of the raw material for winemaking is of vital importance to the quality of the wine produced. Several options exist for winemakers or winery owners: grow their own grapes, buy grapes from local vineyards, or buy grapes to be shipped to them. Before planting even a small vineyard, there are many variables to consider. The selection of the scion (top) of the vine and the rootstock onto which it will be grafted must be such that the two are compatible with each other. There are several growing conditions which will affect the composition of the grape and the quality of the wine. Among these factors are climate, soil, fertilization, irrigation, pest control, virus infections, crop level and other cultural practices. The refractometer is the most commonly used device for measuring sugar in grapes and the better models are temperature compensated. There are hundreds of grape varieties. If hybrid varieties are included, there are thousands.