Nowadays we know multiple onion varieties, classified by the bulb shape, the colour and size. In Spain, three types are distinguished according to the earliness: early, mean-early and late varieties. The onions also are classified by their country of origin and the use they are intended for.

The different onion varieties may be classified according to various characteristics, such as the bulb shape, that can be globose, flat, turbinate, discoidal, pear-shaped, oblate and conical; the dimensions; the colour; the bulb (internal tunics), being this white, yellow or red.

The varieties used in Spain are also classified by their earliness. Among the early varieties there are " Babosa’, " Blanca francesa’ and " Sangre de Buey". Among the mean-early varieties are " Blanca del País", " Amarilla de Cabeza Grande Achatada’ and "De Liria’. To finish with, among the late varieties are " Blanca Grande tardía’, " De grano’ and " Valenciana tardía Recas".

They are also classified according to their origin. In this way, there are Spanish, French, Italian, English, American, Dutch and Japanese varieties.

The English and the Americans distinguish the onions by their flavour. The " soft type’ are characterized by their sweet taste, whereas the " strong type’ has a hot taste. The " soft type’ are usually early varieties and with less contents in soluble solids, whereas the " strong type’ are late varieties that provide more nutrients.

The onions are moreover classified by their use. The bulb varieties are cultivated because of this spare organ. The varieties for salad, which are also known as chives, have a white external membrane of sweet taste. Finally, the varieties for pickle are small bulbs silver external membranes and hot flavour.