The Fermentation of Must on a Large Scale

Large tanks enabled the shippers to approximate all their wines to the best and to achieve a greater uniformity, which was a very real advantage to a large commercial house specializing in a few major brands. However, it was correspondingly a disadvantage to a small, individualistic shipper who wished to offer a wide choice. The scale of the operation in the big bodegas, and the efficiency achieved was indicated by the fact that Diez-Merito could ferment twelve thousand butts in twenty-five days with a labor force of four men and a smaller scale bodega.

During the first half of the nineteenth century, it was quite usual for growers to store the must in their vineyard buildings for the first few months, until fermentation was more or less complete. Then the growers had an alternative idea. During the second half of the nineteenth century, the must was impregnated with the fumes of burnt sulphur by means of a most extraordinary machine. This process delayed fermentation for a few hours and gave time for the casks to be brought into Jerez on donkey and bullock carts.

The sight of those primitive carts led by dignified, ragged Andalusian peasants, rattling through the streets with the new vintage, was a sight for poets, and was still occasionally seen in years following. The old sulphuring machines were not a success, though. The fumes gave rise to a number of sulphur compounds including sulphuretted hydrogen and the fermenting must smelt of rotten eggs. In fact the preservative did more mischief than the sun.

Eventually, the onset of fermentation was delayed by using a carefully controlled quantity of sulphur dioxide solution. This was used even when there was no question of moving the casks, as it discouraged the rather feeble "wild yeasts" and enabled the wine yeast to control the fermentation from the very beginning. When grapes were pressed in small vineyards, it gave a respite for the casks to be taken to the fermentation bodegas in the towns on truck. It seemed a pity that the old carts were abandoned, but the trucks were undeniably better.

During the first half of the nineteenth century, it was quite usual for growers to store the must in their vineyard buildings for the first few months, until fermentation was more or less complete. Then the growers had an alternative idea.