It is hard to say what the types of unmixed or unblended sherry are because so few of them ever reach the consumer.

In general, sherries in their natural or unblended state may be divided into two great groups, namely, wines which develop very markedly the characteristic aroma and taste of the sherry district, and second, wines which for some reason fail to develop this characteristic aroma and taste, but remain only good wholesome beverages affording a fine body for blending purposes. Naturally, the wines of the fragrant and aromatic taste are those which are developed particularly in the old casks. Just what the organism is which produces the characteristic flavor and aroma is not known, but it is supposed to be a species of fungus and is called by the Spaniards "flor." It looks very much like the ordinary mycoderma vini which develops in wineries. The growth of this flor is encouraged and regulated just as our mothers used to transmit the mother of vinegar from barrel to barrel. It may be said that the peculiar sherry taste which distinguishes this wine from all others is due solely to the development and growth of this fungus. The fungus does not grow in wines which are too strong in alcohol and so it is not expected to appear in those of a very high alcoholic content.

The two groups of wine are classed, first, as the Fino Type, a wine which in its early years has been matured with a film of, the flor on its surface and possesses, therefore, a pronounced ethereal taste and bouquet. The second type is the Oloroso Type, a wine which from the completion of its first fermentation has produced so much alcohol that the flor cannot grow upon it and it is, therefore, devoid of that peculiar ethereal taste and aroma which is produced by the flor.