A straw with a filter which is used for drinking yerba mate infusions is called a ‘bombilla’ in Spanish and ‘bomba’ in Portugese. Spanish pronunciation is bombija, Argentinian and Uruguayan people who use the Spanish rioplatense dialect pronounce it bombiga. Bombilla is both a straw and a filter. There are many types and shapes of bombilla and it can be made of a variety of materials.
A bombilla can be between 12 and 26 cm (4.5” and 10”) long. The most popular size is 16 to 19 cm (6” to 8”). The length of a bombilla should be appropriate to the size of the gourd. A small gourd with a long bombilla will tip over. Using a very short bombilla for a large gourd is not practical. Longer bombilla will help cool the drink. Some bombillas have one or more rings to speed up the cooling process. The shape of a bombilla, whether it is straight or bent, depends on the individual preference of the drinker.
There are two basic types of filters used in a bombilla: one is a spring-sleeve, the other is a round or oval shaped ending of the straw with small holes in it. A filter with holes in it is more effective but it can clog up. The oval, spoon like shape at the end of the straw is quite practical because it can be used for removing the mate leaves after use. Sipping mate through a spring-filter straw is a little bit easier but tiny pieces of leaf can get through the filter. A lot depends on the quality of the bombilla. Some bombillas have more than one type of filter, for example they may have a spring filter with a metal mesh underneath it. The better the filter, the more likely it is to clog up. When choosing a bombilla for a small gourd it is important to notice how close to the end the holes are placed. If they are too far, some infusion will remain at the bottom of the gourd which in a small container might be of importance.
Materials used for bombillas:
German silver is an alloy which has properties similar to silver (but does not contain silver), hence its name. A bombilla made from this will be strong and will look attractive. It is usually decorated and may be coated with gold or silver.
A stainless steel bombilla is very strong but relatively inexpensive. It will not rust and will not rub off. Some elements of it, such as the filter or the cooling ring, may be made from other alloys, for example bronze.
Its biggest but only advantage is its low price. Nickel rubs off easily and the outer layer of the bombilla will scale off. It will have to be replaced after a few months. Many people are allergic to nickel. In Europe the number is between 50 and 60 million. European Union regulations forbid the use of nickel in products which come into contact with skin, such as earrings, bracelets, chains, frames of spectacles etc.
A bamboo bombilla is used mainly for serving terere, which is cold yerba mate, although it is possible to use it for warm infusion. Its filters are poor and they will easily let the leaves through or will clog. As it is made from a natural material it does not get hot and will not burn the lips and it costs very little.
It is possible to see plastic bombillas, aluminium or even silver and gold bombillas.