Although it may appear to be hobby of minor interest, the truth is that collecting cava bottle tops is an increasingly popular pastime in Spain, and above all in Catalonia, which
is logical given that 70% of the production of this quality regional sparkling wine (v.c.p.r.d) originates in the Catalan town of Sant Sadurn� d'Anoia. For this reason various associations that share the passion of collecting as many cava bottle tops as are based in Catalonia.

Origin of the bottle tops
The origin of cava bottle tops dates back to the 19th century when a French manufacturer began to use bottle tops that were wider and longer than those used up until then to prevent the liquid and gas of this sparkling drink from escaping. In addition, in order
to hold down these tops and prevent them from popping off due to the pressure of the gas, he had the idea of using a metal bottle top which was first fastened with rope and then later with wire, as is the common practice nowadays.

Since then these bottle tops have become an important marketing tool. At first only the word Champagne or the name of the producer was written. But slowly the producers refined
the practice and become personalising the bottle tops with their own image and brand. Thus the practice of collecting the bottle tops was born, which now has an increasing number of followers the world over. In Spain, the collectors tend to be exclusively of cava, although there are those that also collect other sparkling wines, such as French champagne.

Collection criteria
As in most classes of collecting, the criteria of selection are as varied as the collectors themselves. Hence, some collectors classify their bottle tops according to the year of the production of the bottle they belong to or according to the producers of the cava. However, the most common criteria are the following: on the one hand the type of relief on the bottle top and on the other hand the shapes of the bottle tops.

The cava bottle tops are always decorated with motifs and varying colours in accordance with the style and design of each producer. They can also come carved, stamped, engraved or with a design. There are also cuts in the upper and lower parts to fit the wire that covers them. A final criteria is whether the bottle tops have been used or not. In the latter case they are known as dry tops.

Unwritten rules
As in any form of collecting, the exchange of items is very common and internet has become the main channel of communication between these aficionados. The most curious thing in this respect is that there are laws governing the swapping of items among collectors. These laws are simple and unwritten and some associations present on the Net suggest grouping them together under the Spanish abbreviation DAAC:
Decide beforehand and accept the exchange before sending it. 
Warn the other party if the bottle top is in good condition before sending it.
Agree the way of exchanging the item before sending it.
Confirm the arrival of the top. As simple as that.

A highly active collector�s association
One of the most prominent associations in Spain is the Colleccionistes de Plaques de Cava, a non-profit organisation founded in Barcelona in 1994, which is listed in the Generalitat�s Register of Associations. This is made up of enthusiasts and experts in the matter whose firm aim is to promote the past, present and future of these items, encourage collectors, update the existing documentation on both cava bottle tops and those belonging to other producers of sparkling wine the world over.

Via the magazine La Placa, pamphlets and information sheets, this association informs
its members on the latest developments in the sector and on ways in which to extend
their collection.

They also organise periodical meetings in which members can get to know other collectors and exchange information and material.