Why are sablefish so fatty? What explains the rich flavor and buttery mouthfeel of sablefish that draws so many seafood fans to black cod?
The richness and the omega-3 fatty acids that health-conscious seafood consumers crave are not produced by the sablefish itself but come from the marine environment in which they live. Essential fatty acids are nutrients that work as building blocks for all of life, starting as cell membranes. And these building blocks are key to building many aspects of our lives.
Indeed, sablefish’s health benefits are well known because they contain an extraordinary 1787mg of omega-3s per 100 gram serving—this concentration of omega-3s is higher than any whitefish or salmon. These omega-3s have been shown to reduce inflammation, boost cardiovascular health, protect memory loss and thinking problems, improve mood, and prevent age-related brain gray matter loss. And the omega-3 fatty acids are a main structural component of our brains. These omega-3s come from the ocean. But how?
Omega-3s in marine-derived lipids come from diatoms, single-celled aquatic plants that grow in the ocean’s surface waters. These diatoms are responsible for 40% of marine photosynthesis. And they are also key producers of essential fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Diatoms function like plants converting the sun’s energy into simple sugars that nourish fish, birds and other marine life. But when confronted with stress, say with changes in water temperature, salinity, light, or nitrogen availability, diatoms temporarily stop behaving like plants and become more like fuel cells and batteries. They then produce and store large amounts of lipids as a survival mechanism to warehouse energy through tough times like darkness or temperature extremes. 70% of diatoms’ biomass are life-sustaining oils.
How do these life-sustaining oils and nutrients go from diatoms on the ocean’s surface to sablefish that frequently live a mile deep in the ocean or more? Zooplankton, herring, pollock and crustaceans transmit these nutrients to sablefish which require energy reserves to stay buoyant and warm in the ocean’s deep, frigid waters. Sablefish are voracious and devour herring and pollock and other marine life. What’s unique about sablefish is what they do with the nutrients. For example, Pacific cod, another whitefish that lives in the deep waters and also eat herring and pollock, store the fatty acids in their livers. But sablefish weave the fatty acids through their bones and tissues like a cozy warm blanket. It is not known why this is, but that’s what makes sablefish’s unique rich buttery mouthfeel.
When omega-3 oils are cooked they release volatile compounds—ketones, alcohols, aldehydes associated with a variety of flavors including meatiness. Once airborne, these molecules float to olfactory receptors in our noses, transmitting an aroma that combines with flavor molecules on our tongue resulting in the rich sensation you get when eating black cod, in addition to its buttery mouthfeel.
In addition to the health benefits that come from the marine-derived lipids in sablefish, there comes another huge benefit for us seafood lovers: it is extremely difficult to dry out sablefish when cooking. There are so much fatty oils in sablefish that it’s almost impossible to dry it out in the oven. Another benefit is that sablefish can work perfectly in banquet situations. Salmon tends to dry out in banquet when it’s sitting under bright heat lamps, but sablefish does not. If you’re planning a dinner with a banquet-style setting, we highly recommend sablefish, a fish that absorbs the nutrients of unique marine environment to produce high-quality nutrition for us.
