This is how the most advanced treatment plant in the world works, from the tray to the washing tunnel

This is how the most advanced treatment plant in the world works, from the tray to the washing tunnel

We are in one of the 3,337 trays that there is in Galicia. They produce around 300,000 tons of mussels. A little more is produced in China, but there a good part of its production – of lower quality – is used for fish farming, as food for other fish. Galicia is, therefore, the world’s leading power in marketing mussels to the final consumer.

These floating artifacts have been evolving since, in 1945, the builder Alfonso Ozores Saavedra mounted the first Galician batea of ​​which there is evidence. It was more rudimentary than the ones that exist now, but its operation is essentially the same: a wooden frame that floats on the seafrom which ropes hang from which the mussels are grown, which feed on the phytoplankton that enters from the sea through the estuary.

The number of rafts in Galicia has been the same for decades, when their construction was limited to preserve mussel farming. Since then, you are Administrative concessions, that are renewed every 50 years, are only transferred from parents to children or by paying a license transfer which is not cheap: depending on the area in which it is located –not all are equally productive– they can be worth a million euros.

“The rafts that produce the most are those that are at the mouths of the estuaries because they are the ones that eat the most phytoplankton,” he explains. Oscar Sandias, a bateiro supplier of Linamar, one of the largest sewage treatment plants in Galicia, based in Cambados (Pontevedra), which, since February of this year, has been owned by the fish products giant Angulas Aguinaga.

Mussels take between a year and a half and three years to reach commercial size

His raft is in the Arousa estuary, the largest and in which 67% of all those in Galicia are installed. “The mussels are differentiated according to the estuaries”Sandias explains. “Here they are more orange, more powerful, stronger. They also get fatter.”

Mussels, in any case, take between a year and a half and three years to reach commercial size, a time that hardly anyone expects anymore. “Before they had it two and a half or three years,” explains the bateiro. “This has changed for a long time, they are taken out before and work is being done to make them more homogeneous and then it is sorted, the smaller ones are sold fresh or to France”.

Much of the bouchot mussel, which should be raised in Brittany and Normandy, actually comes from Galicia. Among the bateiros this mussel, not without some sarcasm, is known as “lacasito”. And, since it is not appreciated in Spain, the French eat it.

Sandia lifts freehand one of the ropes from which hundreds of mussels hang.

A day’s work on the punt

All Galician rafts are practically the same. By law. Have 500 m2 and from its beams hang exactly 500 strings, with a length of 9 to 12 meters. The young mussels that are collected from December to March on the coast are placed in them, in areas authorized by the Xunta.

Percebeiros and bateiros maintain a bitter dispute

“Now they are controlling more the issue of breeding”Sandias explains. “From 20 years to here it is noted that the mussel is weaker, spawning is cut off. It spawns once or not at all and used to spawn two or three…”

The boundary has generated an angry dispute between bateiros and percebeiros, who share these breeding areas. Dispute that, in various parts of Galicia, has led to aggression from both sides.

The bateiros complain that the barnacles catch mussels as well as barnacles and they resell them illegally, as it is not legal to trade mussels below 4 cm. The percebeiros, however, accuse the bateiros of destroying the barnacle when they scrape the rocks to stock up on cheek (as the mussel hatchling is known).

Mussels Water

This is what mussels look like underwater.

Bateiros have a job more similar to that of a farmer than that of a fisherman. In a notebook they write down how each line of the raft goes, to put in and take out the mussels at the right time. As the mussels grow, they unfold: after six months they have a size of two centimeters and are distributed among more strings.

“There are two of us and we do all the work, before there were six or seven people,” explains the bateiro

When the mussels are ready to be removed, the ropes can weigh between 30 or 40 kilos. Before they were removed by hand. Nowadays, the boats have a crane with which all the mussels are extracted, which in many cases is cleaned and weighed already on the boat.

“There are two of us and we do all the work, before there were six or seven people,” explains the bateiro. While Sandias attends to the journalists, his partner walks around the batea with a harpoon in hand. The fish will feed on the mussels and, if you try not to let them see your shadow, it is easy to catch them. Today someone is going to have peixe porco for dinner.

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Sandia owns five rafts, in which he grows mussels all year round. In a notebook he notes when each rope has been cultivated.

to the treatment plant

The success of the Galician mussel could not be explained without the other great actor in the industry who is, in the end, the one that controls it: the purifiers. These companies, usually located along the coast, process the mussels so that they are safe to eat, and distribute them fresh or, as our hosts also do, in prepared dishes.

“We clean it because the consumer wants it clean, but there is nothing wrong with it,” admits Solla

The mussel is a filter feeder: It feeds on phytoplankton and other organic matter present in seawater. And, although there are areas of the estuary where live mussels can be eaten safely, there is a risk that they transmit toxoinfections such as Salmonella or E.Coli. It is therefore mandatory to purify the mussel before it is sold: something that is achieved by feeding the mussel with previously disinfected seawater for a period of time.

At the Linamar treatment plant, which today belongs to the Angulas Aguinaga group, 140 employees work, who purify, clean and select the mussels, in what is, they say, the most advanced mussel processing facility in the world. so much that we are not allowed to engrave any image of the interior of the factory due to industrial property issues: we can only use the photos provided by the company.

Galicia has the key to feed a hungry humanity: mussels

how do you explain to us Dori Solla –former owner of Linamar and currently head of the plant–, the success of her treatment plant has been based on her efforts to present the cleanest mussel possible, free of beards, crags (the remains of fossilized worms) and arneirón (the small crustaceans that stick to the shells).

“We are the leaders in cleaning mussels,” says Solla. “We clean it because the consumer wants it clean, but there is nothing wrong with it. You would be surprised by the number of trays that we sell to restaurants in the campaign so you don’t have to clean them with the lullaby”.


Dori Solla, head of the Cambados de Angulas Aguinaga plant, has been working with mussels all her life.

The cleanest mussel in the world

At the plant, the mussels, after going through the treatment plant itself, and still alive, go through a car wash complex in which they are carefully selected, cleaned and brushed. The company even has a self-developed machine that cuts the beards of the mussels instead of pulling them out, which causes an injury to the mussel that can compromise its life.

A artificial vision machine then identifies the mussels ready to reach the final consumer, but it is not yet very well calibrated. From the time it leaves the cleaning chain until it is packaged, we count at least 10 operators who check the mussels by hand.

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Given how thorough this selection is, around 20% of the mussels that arrive are discarded and are used for animal feed. A figure that we are trying to reduce, explains Solla, making the most of the purchases from the bateiros: “We buy from different associations every day. We make samples of how much the mussel food weighs per kilo and cleanliness studies, food weight and size. If there is arneirón and risco they cannot go to elaborate dishes. We buy everything and depending on what is in the sewage treatment plant, we do one thing or another and adjust the purchase”.


Throughout this cleaning process the mussel is under great stressTherefore, between wiggling and wiggling, it is always immersed in disinfected seawater with a controlled temperature. Linamar is the Willy Wonka of mussels: there are dozens of tubes filled with seawater through which the mussels pass from one side to the other.

“After all it is rattling has a very altered metabolism, That is why it is important that he relaxes, calms down and shuts his mouth, which are his optimal conditions,” one of the plant’s quality managers explains to DAP. “It has to contain interbalval water. And for the processed ones too, it gives flavor, texture and juiciness.”

Mussel with tomato Aguinamar 500 g

Mussel with tomato Aguinamar 500 g

The mussel is distributed live, fresh to conventional fishmongers, or Packaging in protective atmosphere for supermarkets and hotels, but this plant also manufactures mussel preparations: at the end of the entire cleaning and selection process, they are cooked with a series of sauces in some huge autoclaves which, Solla jokes, “cost like a villa in Sansenxo grande”.

Now yes, the mussel is cooked, pasteurized and ready to eat, to be marketed in Spain under the Aguinamar banner, and outside our country with other group brands. The French, again, get the small mussel. But with butter.

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