How your Rosita Extra Virgin Cod Liver Oil is created

From fish to bottle! Learn about the production of Rosita fish oil, its one-of-a-kind patent, and how to tell if your cod liver oil is truly unprocessed

“As far as we’re concerned, there is only one way of producing fresh, genuine and authentic cod liver oil. And that is by using the methods employed by our ancient forefathers.”

— Bengt Svensson, Rosita Real Foods

Rosita versus standard cod liver oil

Rosita is unprocessed and pure, which means it retains all of its precious, naturally occurring nutrients and it meets strict European standards for safety.

Here’s a wealth of information on how your Rosita Extra Virgin Cod Liver Oil is created, compared to standard, commercially produced cod liver oil.

As transparency is of the utmost importance to us, especially given all of the misinformation out there about fish oils, we want you to completely understand our extremely gentle production process — that yields the highest quality, most nutrient-rich cod liver oil on the market. 

The Rosita Method

The ancient Rosita method

1. Wild-caught, deep-sea fishing: We sustainably fish the wild codfish (Gadus morhua) from the pristine, sapphire blue waters of the Norwegian fjords. To ensure total control over sustainability, quality and freshness of cod livers, we employ our own small artisan fishing boats (rather than commercial fishing boats). Our boats put out sea bird-friendly long lines baited with fat slices of frozen mackerel or herrings. We catch the cod carefully to protect the population. Line-caught fish are a much better alternative to fish that have been caught by destructive trawling methods. And sustainable, fresh cod tastes so much more clean and sweet!

The liver oil from deep-sea cod was highly prized and sought after by the ancient Norse people, who considered it to be the most potent in terms of therapeutic properties. It was also known to have a smoother consistency. Our ancestors were masters of deep-sea fishing; grueling yet rewarding work.

Commercial CLO: Manufacturers of commercial cod liver oil do not specifically fish for deep-sea codfish. They will often purchase fish on the open market or from brokers, which can be problematic regarding the freshness, source, and even fish species. By using freshly-caught fish and not importing frozen products, we believe quality is optimally maintained and the properties of the raw materials will not deteriorate during long transport, freezing, etc.  

2. Harvesting the livers on deck: Next, we haul the lively wild codfish into the boat and remove them from the hooks. Our fishermen then carefully sacrifice the fish, remove the livers, and wash them in pure cold water. The livers are then immediately placed under proprietary conditions to maintain freshness. We separate the meat and insides for other uses, and quickly ferry the livers to shore.

3. Inspecting the livers by hand: Upon returning to the docks, we carefully hand-inspect the fresh livers at Rosita’s zero-emission production premises. We go to great lengths to make sure the livers are carefully handled and never exposed to high temperatures, chemicals or reactive metals. This is because rough handling of the liver can cause it to bruise, promoting degradation and lowering the quality of the oil produced. Per ancient Viking tradition, we only use fresh, robust livers of a specific appearance and weight, as the quality of fish liver oil is highly dependent on the quality of the liver. That means crushed and bruised livers don’t apply. Further, if the cod livers are small and discolored (or have a dark appearance), this indicates a scarcity of food for the cod and the possibility they may not be healthy. The best codfish livers are large and beautifully plump, soft to the touch with an almost cream-colored appearance, which indicates the codfish are thriving and well-fed. Such livers contain an abundance of quality oil that appears perfectly pellucid and pale-colored with a mild, fresh fish taste.

4. Releasing the oil from the fresh cod livers: Our ancient method for cod liver oil extraction is extremely rare. And it produces the most precious cod liver oil naturally. 

Here’s how it works: We create a gentle shift in temperature, from the icy cold water that the fresh livers are submerged in upon harvest, to below-room temperature. This shift naturally triggers the release of the oil. 

This shift is also done in the total absence of heat, which protects the oil’s nutritional value. Just as important, we never subject the livers to chemical treatment, solvents, mechanical devices, rendering, Peter Möller’s method (steam), distillation, winterization, putrefaction, decomposition, alkali refining, bleaching, deodorization or freezing (these are dirty words to us at Rosita!). We take every precaution to preserve the therapeutic properties of cod liver oil and its natural abundance of nutrients.

This method is so rare because the only way to carry out the subtle temperature shift is to control each step from fish to bottle. Great care for the livers is taken throughout each step, so they maintain the optimal temperature that allows the fresh oil to naturally release. 

To further understand how we release the oil from the fresh cod liver oils, here is some history:

The ancient Norse people observed that the appearance, size and texture of fish livers vary considerably depending on the seasons. For certain seasons, the livers were beautifully plump, with a light cream color and very soft to the touch, bursting with oil of superior quality. During other seasons, the livers were smaller, with a reddish hue, firmer to the touch, with low oil content. The ancient Norse people also knew both air and water temperature vary from season to season and believed the water temperature influenced the physical characteristics of the liver. As such, they discovered those plump, cream-colored oily livers could revert to their smaller, reddish form by releasing the oil they contain. The trigger for releasing their oil was a change in temperature which mimicked specific seasonal changes in water temperature. How did they do it? By transferring freshly removed fish livers to slightly warmer dwellings than the cold ocean in which the fish lived. The livers would then naturally and gradually release the raw, pale golden oil in their cells without any intervention. This gave rise to the basic oil extraction principle that the ancients went about perfecting and that Rosita uses today, where nature does all the work.

5. Gentle filtration: Immediately after the oil is released, it is very lightly filtered, with the help of a special patented method that uses gravity only, at low temperatures. This method simply removes particles of liver tissue, without refining the oil. In contrast, conventional procedures remove most of the healthy, fat-soluble vitamins, and therefore, commercial producers will add synthetic vitamins to make up for the loss (for more, see How to tell if your cod liver oil is unprocessed, below). 

6. A drop of natural antioxidants: We add tiny amounts of the plant rosemary and natural, GMO-free vitamin E extract from sunflower seeds to maintain freshness.

7. Bottling: We then bottle the oil in amber glass to extend its shelf life and freshness by protecting it against light. The bottle is then nitrogen-flushed, to preserve freshness by removing oxygen (this ensures safe shipping in all temperatures). The result is 100% unadulterated, wild and raw Extra Virgin Cod Liver Oil, which contains absolutely no synthetic nutrients. 

8. Testing: Samples of each batch of Rosita Extra Virgin Cod Liver Oil are third-party tested in a microbiological laboratory and certified to meet strict European regulations for potency and purity. Read the results here.

The world’s only patent for heat-free and chemical-free filtering

Rosita is the only company to hold a patent for a truly gentle chemical-free and heat-free method to purify your cod liver oil, developed with support from the University of Stockholm. 

This extremely unique method uses a natural substance from the ocean that binds to contaminants in the oil, followed by filtering — like decanting a fine wine. It is highly effective at reducing contaminants but does not alter or damage the oil’s nutrients in any way. (Here’s more information about the nutrients inside your Rosita Extra Virgin Cod Liver Oil.)

No other company has this patent, which means that every other cod liver oil
producer has to use heat to cleanse their oils. 

How to tell if your cod liver oil is unprocessed

This simple-myth buster can help dispel the serious misinformation on what heat can really do to the precious nutrients in cod liver oil. 

Myth: Other manufacturers tout the benefits of “low heat molecular distillation” for cleansing cold-pressed oils, which may seem like the result is raw or gently processed.

Truth: Cold pressing just refers to the extraction of the oil from the liver. Once extracted, however, commercial oils are subjected to high heat during the degumming (212° F), deodorization (374° F or higher), and molecular distillation (392° F) steps. This extreme processing with heat wipes out the natural vitamins A and D — and damages the fragile omega-3 fatty acids. To make up for the loss, most cod liver oil producers will add synthetic vitamins.

  • Only Rosita uses a rare, generations-old technique that naturally releases the oil from the hand-picked livers (with water at temps akin to the ocean). This can only be accomplished with healthy livers from freshly caught cod.
  • Only Rosita has a patent involving the rare use of a natural substance from the ocean that binds to contaminants in the oil, followed by gentle filtering. As we touched on above, this successfully reduces contaminants without changing or damaging the oil’s rich nutrients.

This all means your body will recognize Rosita Extra Virgin Cod Liver Oil as real food, not a processed supplement. 

Our In-House Expert

Formulated by a Ph.D. Scientist specializing in Nutrition & Marine Oils

Rosita fishing boat

Dr. Pieris Andrew Nicola, Ph.D., Chief Science Officer

Dr. Pieris Andrew Nicola is the Rosita family's scientist and products/nutrition specialist, who leads our research and development. He is a graduate of the University of Oxford, with a specialty, and multiple degrees in nutrition. Dr. Nicola is a leading authority in his field and also among the best in the sciences of marine oils.