Last week, we learned the results of a blind taste test that pitted frozen scallops against fresh.

The results — which favored frozen scallops — probably surprised many people but wouldn’t surprise anyone who works closely with seafood.

As New York Times health columnist Jane Brody once said, “The freshest seafood is that which has been frozen shortly after harvest and remains that way until cooked.”

But most people still tell pollsters they prefer fresh fish, mistakenly believing that never-frozen seafood is healthier, higher quality, and more local.

In reality — unless you buy seafood caught the same day — much of the fish and shellfish labeled “fresh” has spent days in transit and in refrigerated storage and may then spend hours or days in a supermarket seafood case.

Unfortunately, the pervasive but misguided preference for “fresh” fish persists, harming America’s small-boat fishermen, who — for excellent reasons — increasingly flash-freeze their catch upon or within hours of harvest.

Consumers’ misperception of frozen seafood — and the harm it causes American fisherfolk and their communities — prompted Ecotrust and Oregon State University to collaborate on blind taste tests and technical analyses of fresh and frozen fish, starting in 2016.

For the most recent test, the researchers invited nearly 100 consumers to participate in a November 1 blind taste test of fresh and previously frozen scallops at Oregon State University’s Food Innovation Center.

The participants tasted seared scallops of undisclosed status — some fresh and some previously frozen — and scored each sample for texture, flavor, aroma, appearance, and more.

The taste-testers scores aren’t available yet, but the participants interviewed by Seattle’s KUOW said they detected no clues as to the fresh or previously frozen status of scallops they’d sampled.

We strongly suspect that frozen scallops will either win or tie with fresh, because frozen fish has beaten fresh in all prior tests conducted by Ecotrust and OSU.

Prior tests found flash-frozen fish superior to fresh
Three years ago, Oregon State University (OSU) teamed with Ecotrust to conduct the first technical analyses and blind taste tests designed to compare fresh to previously frozen fish.

The goal of the study was to address the fact that most consumers assume frozen fish is less fresh and less tasty than its unfrozen counterpart.

As in the new scallops test, the OSU/Ecotrust team used two methods:

  • Blind taste tests pitting previously frozen fish against fresh.
  • Analysis of freshness via a validated device called the Seafood-Certified Quality Reader (CQR).

The first OSU/Ecotrust tests involved fresh and frozen samples of wild silver (coho) salmon and sablefish (also known as black cod or butterfish) that'd been harvested by small-boat fisherman in Oregon and Alaska.

Since then, consumers have sampled and blind-judged fresh and frozen albacore tuna, sockeye salmon, rockfish, and — as of last Friday — Alaskan scallops.

One day prior to a blind taste test, frozen fish fillets were stored in a 36°F refrigerator to thaw. Fresh samples of the same species were purchased the morning of the test from high-end grocery stores.

The fresh and (recently thawed) frozen samples were then baked without seasoning, assigned a three-digit code, and served in random order to the more than 100 participating consumers, who were scored each sample for aroma, flavor, texture, quality, overall appeal, and the participant’s likelihood of purchasing it.

And, in each of the separate species tests, the participants ranked flash-frozen fish as equal to or better than its fresh counterpart.

And when test participants were asked to pick from multiple descriptions of fish they’d sampled, they overwhelmingly chose “recently caught and fresh out of the ocean” to describe the taste of previously frozen fish.

The scores from blind taste tests of sablefish (black cod) were typical:

  • 57% of participants ranked the quality of frozen sablefish as “above average” to “excellent.”
  • 70% of participants ranked the quality of fresh sablefish as “average” to “poor”, and two-thirds said they would “definitely not” or “probably not” buy it.

Technical analyses also favored frozen fish
In addition to blind taste tests, the researchers used the Seafood-Certified Quality Reader (CQR) developed by a company called Seafood Analytics to measure product quality and freshness.

The CQR device sends a low-frequency electrical current through fish, collects data based on its relative conductivity, and assigns it a Certified Quality Number (CQN).

A higher CQN indicates a fresher, higher-quality fish. For example, a just-harvested fish will typically register the maximum score of 100, while a fish that that’s been refrigerated for several weeks will score less than 10.

A fish that has begun to decompose, or has not been handled carefully, will contain more conductive fluid because its cell membranes have begun to break down, causing it to become mushy. In contrast, the cell membranes of a freshly-caught fish are still intact, making it firm and resistant to conductivity.

Reflecting the results of the blind taste tests, the CQR device registered higher Certified Quality Numbers (maximum being 100) for previously frozen fish versus fresh fish. For example:

  • Frozen coho (silver) salmon scored 79 vs. 20 for fresh.
  • Frozen sablefish (black cod) scored 80 vs. 15 for fresh.

This graph shows the reactions of the blind taste-testers to the frozen and fresh sablefish and salmon, with frozen winning big in both cases:

The fresh-versus-frozen studies have received financial and other support from the National Fish and Wildlife Foundation, various seafood industry groups, and Oregon Sea Grant.

Why the test results matter so much
OSU and Ecotrust decided to conduct technical and blinded taste tests because they are concerned about small-boat American fishermen, who fish sustainably but struggle to compete with imported seafood.

On average, imported seafood accounts for 90% of fish and shellfish sold in the U.S., and about one-third of those imports are illegal, unregulated, and unreported. For more on that, see Illegal Fishing Fuels Fraud and Slavery with Your Shrimp?.

To counter foreign competition, American fishermen have begun to market their catch direct to retailers and consumers, and some have formed “communities supported fisheries”, which are the oceanic counterparts to farms in which consumers buy memberships and receive shares of the harvest and return.

To capture and preserve the fresh-caught quality of their catch, small-scale fishermen must flash-freeze their seafood (at -40°F or colder), either on board their boat or very soon after arriving on shore.

As Washington-based scallop and crab fisherman Jim Stone told Oregon Public Radio, “We often get asked by chefs to bring in fresh scallops. Because of the remoteness of where we fish it gets really difficult to do that and for any reasonable price. A fresh scallop can be on a boat as long as 10 days before it even lands at the dock and then it may take another week before it gets to the consumer.”

Stone added that his boats save fuel by harvesting, processing, and freezing at sea, which avoids repeated trips to deliver their fresh catch to port.

When paired with careful harvesting and handling of fish, flash-freezing, preserves the quality of fresh-caught seafood perfectly. Flash freezing also allows small fishermen to avoid the price volatility of the fresh-fish market and considerably extend the shelf life of their catch.

Better yet, flash-freezing reduces waste of fish parts, lowers carbon emissions, and delivers seafood of unsurpassed, truly fresh-tasting quality. (For more about waste and carbon emissions, see Alaskan Fisheries Seen as Least Wasteful and Frozen Wild Fish Found Greener than Farmed Salmon or Fresh Wild Fish.)

As famed seafood chef and author Barton Seaver told the Washington Post last year, “It [frozen seafood] is a major win for sustainability. It decreases waste and takes advantage of seasonal bounty to spread its availability throughout the year.”

And as OSU researcher Ann Colonna told Seattle’s KUOW radio station, “One third of all seafood is actually thrown away at the counter because people are not buying it quickly enough. To have more acceptability around frozen product is just going to help everyone.”


  • Ecotrust/Tyson Rasor. Taking a fresh look at frozen fish. July 26, 2017. Accessed at
  • Northwest News Network/Tom Banse. Take a fresh look at frozen seafood and prepare to be surprised. Nov 06, 2019. Accessed at