An old method of viticulture whereby different grape varieties are planted within a single vineyard. The grower then harvests all of the grapes at the same time and ferments them together. Thus, the final blend of the wine is based on the percentages of the varieties in the vineyard. If about 20% of the vineyard was planted with syrah, then the final wine will be composed of about 20% syrah. Before the 20th century, most blended wines were based on field blends. Today, vineyards (or at least blocks within a vineyard) tend to be planted with a single variety. The grower can then harvest that variety when it is optimally ripe and ferment it separately, in order to evaluate it before using it in the final blend.