Bonito del Norte: the complete guide to premium Spanish tinned tuna
There is a world of difference between the tinned tuna most of us grew up with and a jar of genuine Bonito del Norte from the Cantabrian coast. One is a commodity. The other is a gourmet ingredient — line-caught, hand-prepared, and preserved in extra virgin olive oil by craftspeople who have been doing it the same way for over a century. This guide explains what Bonito del Norte actually is, why it is considered the finest tinned tuna in the world, what Ventresca is and why it commands a premium, and how to use both in your kitchen.
What is Bonito del Norte?
Bonito del Norte is the Spanish name for albacore tuna — Thunnus alalunga — a long-finned species fished in the Bay of Biscay and along the Cantabrian coast of northern Spain. It is a seasonal fish, caught between June and October when the warm Atlantic currents bring the shoals close to shore. What distinguishes it from the yellowfin or skipjack tuna found in most supermarket tins is its flesh: pale ivory rather than pink or brown, with a delicate, mild flavour and a naturally firm yet tender texture that holds together beautifully when preserved in oil.
In the Basque Country and across northern Spain, Bonito del Norte is not a pantry staple — it is a source of genuine regional pride. The best producers catch each fish individually using traditional pole-and-line methods, selecting only the finest specimens and preparing them entirely by hand. This approach is more expensive and labour-intensive than industrial netting, but it produces a product of entirely different quality: minimal bycatch, no damage to the fish, and complete traceability from sea to jar.
What is Ventresca?
Ventresca is the belly cut of the tuna — the richest, most prized and most perishable part of the fish. The belly muscles do less work than the rest of the body, which means the flesh is softer, fattier, and more intensely flavoured. When preserved in high-quality olive oil, the result is a melt-in-the-mouth texture and a depth of flavour that is genuinely extraordinary — closer to a fine charcuterie than to anything you would associate with a tin of tuna.
Because only a small portion of each fish yields Ventresca-quality belly, it commands a significant premium and is produced in limited quantities. It is typically eaten simply — on toast, with a drizzle of olive oil, alongside a few olives and a glass of chilled white wine — rather than cooked, which would be a waste of its exceptional texture.
Conservas Serrats: five generations of Basque craftsmanship
Conservas Serrats is a fifth-generation, family-run producer based in Bermeo on the Cantabrian coast — about an hour from San Sebastián, a city famous for having the world's highest concentration of Michelin-starred restaurants per capita. Founded in 1890, Serrats has spent over 130 years refining a single craft: preserving the finest Bonito del Norte from the Bay of Biscay to the highest possible standard.
Every jar of Serrats tuna begins with fish caught one by one using traditional line methods, selected individually for quality, then gently steamed, hand-trimmed, and packed by skilled processors before being covered in olive oil and sealed. There are no shortcuts, no mechanised filleting lines, and no compromises on raw material quality. Several Serrats lines carry MSC (Marine Stewardship Council) certification, independently verifying the sustainability of their fishing practices.
The result is tinned tuna that tastes fundamentally different from anything produced at industrial scale — silky, clean, and genuinely delicious eaten straight from the jar.
Our Serrats range
Serrats Bonito del Norte in olive oil
The classic Serrats expression: Bonito del Norte loins in extra virgin olive oil, line-caught in the Bay of Biscay between June and October, hand-packed in extra virgin olive oil. The glass jar allows you to see exactly what you are buying — pale, generous loins with no filler, no broth, no broken pieces. Serve on sourdough with roasted peppers, flake into a salad, or use as the centrepiece of a Spanish-style tapas spread.
Serrats Bonito del Norte in organic olive oil — MSC certified
The same line-caught Cantabrian albacore, preserved in certified organic extra virgin olive oil. MSC certified for sustainable sourcing. The organic oil adds a cleaner, lighter note to the fish, making it particularly good for salads and dishes where the tuna is the star.
Serrats Bonito del Norte in water
For those who prefer their tuna without the richness of olive oil, this version preserves the fish in spring water with a touch of sea salt. The artisanal preparation process is identical — the same hand-selected loins, the same careful steaming and hand-packing — giving you the pure, clean flavour of the tuna itself. High in protein, omega-3 fatty acids, vitamins, and minerals, and naturally lower in calories.
Serrats Ventresca in olive oil
The most prized cut in the Serrats range. Belly fillets of Bonito del Norte, preserved in premium olive oil — extraordinarily tender, buttery, and rich. Serve at room temperature on good bread with a pinch of sea salt, alongside olives and a glass of txakoli or Albariño. This is not everyday tuna. It is an ingredient for moments when you want something genuinely special.
Bonito del Norte versus regular tinned tuna: the key differences
Understanding what separates Bonito del Norte from standard tinned tuna helps explain both the price difference and why, once you have tried the real thing, it is difficult to go back.
Species: Standard tinned tuna is most commonly skipjack or yellowfin. Bonito del Norte is albacore — a milder, paler, more delicate fish.
Fishing method: Most commercial tuna is caught using purse seine nets or Fish Aggregating Devices, which catch large volumes quickly but with significant bycatch. Serrats uses pole-and-line methods, catching each fish individually.
Processing: Industrial tuna is mechanically separated and often mixed with brine, vegetable broth, or thickeners. Serrats tuna is hand-prepared, loin only, packed in proper extra virgin olive oil or spring water.
Flavour and texture: Standard tinned tuna is often dry, flaky, and strongly flavoured. Bonito del Norte is tender, moist, and delicate — much closer to fresh fish in both texture and taste.
Sustainability: Line-caught albacore has a significantly lower environmental impact than purse-seine fishing of skipjack. Serrats' MSC-certified lines have been independently verified for sustainability.
How to use Bonito del Norte and Ventresca
Straight from the jar
Both Bonito del Norte and Ventresca are good enough to eat on their own, at room temperature, with nothing more than good bread and a little olive oil. Bring the jar to room temperature before opening — cold oil mutes the flavour of the fish considerably.
On toast or crostini
Spoon generous loins of Serrats Bonito del Norte onto toasted sourdough, add a few capers, a drizzle of extra virgin olive oil, and a squeeze of lemon. For Ventresca, a pinch of good sea salt and nothing else — the fish does not need embellishment.
In salads
Flake Bonito del Norte into a salad of mixed leaves, white beans, cherry tomatoes, and sliced red onion. Dress with extra virgin olive oil and a splash of sherry vinegar. The tuna adds protein, depth, and a Mediterranean character that transforms a simple salad into a proper meal.
Spanish tuna-stuffed piquillo peppers
One of the finest things you can do with premium tinned tuna. Fold Bonito del Norte loins into a fresh allioli with a few capers, a squeeze of lemon, and chopped parsley. Stuff generously into piquillo peppers and serve on slices of toasted baguette with a drizzle of olive oil. A perfect pintxo and an easy, impressive starter.
Tunisian grilled salad — Slata Mechwiya
This smoky, textured salad is one of the great dishes of North Africa. Char green peppers, red chillies, tomatoes, and onion directly over a flame or under a grill until blackened. Peel, hand-chop — never blend — and season with olive oil, lemon juice, and caraway seeds. Arrange on a plate and top with flaked Serrats tuna, halved boiled eggs, black olives, and fresh parsley. Serve with crusty bread. The contrast between the smokiness of the vegetables and the clean flavour of the tuna is extraordinary.
Pasta with tuna
Flake Bonito del Norte into a pan with olive oil, garlic, a pinch of dried chilli, and chopped parsley. Toss with spaghetti and a little pasta cooking water. Add a squeeze of lemon and serve immediately. One of the simplest, most satisfying pasta dishes you can make in under twenty minutes.
Frequently asked questions about Bonito del Norte and premium tinned tuna
What is the difference between Bonito del Norte and regular tuna?
Bonito del Norte is albacore tuna — a long-finned species caught in the Bay of Biscay between June and October. It has pale, ivory flesh, a mild and delicate flavour, and a firm but tender texture that is noticeably different from the skipjack or yellowfin tuna found in most supermarket tins. Standard tinned tuna is typically caught by industrial methods, mechanically processed, and packed in brine or water. Bonito del Norte from Serrats is line-caught individually, hand-prepared, and packed in extra virgin olive oil — a fundamentally different product in terms of quality, flavour, and sustainability.
What is Ventresca tuna?
Ventresca is the belly cut of the tuna — the fattiest, most tender and most prized part of the fish. Because it comes from the muscles the fish uses least, the flesh is softer and richer than loin cuts. Only a small amount of Ventresca can be obtained from each fish, which makes it relatively rare and more expensive. Serrats Ventresca is best enjoyed simply — on bread, at room temperature, with minimal accompaniment — to fully appreciate its buttery texture and concentrated flavour.
Is Bonito del Norte sustainable?
Serrats' Bonito del Norte is caught using pole-and-line methods, fishing for individual fish rather than netting large volumes at once. This approach significantly reduces bycatch and has a much lower environmental impact than industrial purse-seine fishing. Several lines in the Serrats range carry MSC (Marine Stewardship Council) certification, which independently verifies that the fishery meets rigorous sustainability standards.
How should I serve premium tinned tuna?
Always bring it to room temperature before serving — cold olive oil mutes both the flavour of the oil and the delicacy of the fish. For Ventresca, the simplest approach is best: on good bread with a pinch of sea salt and a drizzle of extra virgin olive oil. Bonito del Norte works beautifully in salads, stuffed into piquillo peppers, folded into pasta, or served as part of a tapas spread.
What is the difference between tinned tuna in olive oil and tuna in brine?
Tuna in olive oil is richer, moister, and more flavourful — the oil permeates the fish during preservation and adds its own character to the overall taste. It is the traditional Spanish and Mediterranean approach and is generally considered superior for eating straight or in simple preparations. Tuna in water is leaner, lower in calories, and has a cleaner, more neutral flavour that some people prefer for cooked dishes or when they want the pure tuna flavour without the richness of oil. Serrats offers both options, with the same hand-prepared quality in each.
Where is Serrats tuna caught?
Serrats sources its Bonito del Norte from the Bay of Biscay and the wider Cantabrian Sea, off the coast of northern Spain. The fish are caught seasonally between June and October, when the albacore shoals migrate into the warmer coastal waters. Bermeo, where Serrats is based, has been a centre of Basque fishing and fish preservation for centuries — its canneries and fish markets are among the most respected in Spain.
About the author: Yacine Amor
Yacine Amor is the founder of the Artisan Olive Oil Company, a London-based importer and distributor of award-winning extra virgin olive oils and Mediterranean fine foods, established in 2016. A trained olive oil sommelier, Yacine has tasted and sourced ingredients across Italy, Spain, Tunisia and the wider Mediterranean, working directly with some of the world's most decorated artisan producers. The Artisan Olive Oil Company is certified organic by the Organic Food Federation and is a member of the Guild of Fine Food.