The Aromas That Define Freshness In Eastern Oysters

Brininess – that unique smell of the sea – is associated with the true (edible) oyster. It’s particularly noteworthy in Crassostrea virginica, the scientific name for the Eastern Oyster, which is what we raise here on Long Island, NY.

An Eastern Oyster Should Be Briny On The Nose

Brininess is a measure of freshness, itself the most important quality for oysters in the raw, half-shell market. A quick sniff test is a way to decide if a raw oyster is ready to be enjoyed. What you’ll be inhaling are molecules of odors that scientists have identified as defining freshness.

Never been To the Sea? Smell An Eastern Oyster

A raw, fresh Eastern Oyster (C. virginica) smells mildly of seawater and the seaside. Scientists identify these odors as seaweed-like, “planty,” fruity and flowery, produced by volatile organic compounds (VOCs.) According to researchers, those are the aromas that signal freshness.

These VOCs are aromatic compounds made by the food oysters take in and absorb, and which become part of the oyster itself. We are what we eat, after all.

Scientists researching Eastern Oysters identified the odor-active aldehydes and ketones that contribute to freshness.

Researchers describe the fresh aromas in these aromatic compounds as - – get ready -- canned corn, grass, green, plant-like, metallic-like, melon-like, cucumber-like, as well as marine, fresh, and flowery (lilac).

Brininess Has A Savory Smell

The savory aroma in a fresh Eastern oyster is produced by dimethyl sulfide, (DMS), a gaseous aromatic organosulfide compound that algae makes when it feeds, and is in turn eaten by oysters, who make their own DMS.

DMS is the source odor that scientists liken to the smell of canned corn. Thank DMS if you like the savory flavor it imparts to milk-based oyster chowders and stews..

The aroma(s) in Eastern Oysters associated with the seaside are also attributed to DMS. This odorous gas is found in sea air, and even acts as a GPS by helping birds and animals find the sea.

Briny Smells Don’t Include Salt

Scientists didn’t associate salts with freshness, per se, and when you sniff an oyster, even though it’s salty, you won’t detect a salty odor. That’s because most salts have none, or very little, if any. Saltiness is noticed as a sensation, when you put the oyster inside your mouth and your salt-specific taste buds react.

A cook can dissolve salt into water and call it brine. It will, however, lack the brininess of being briny, which can only come from marine life in the sea.

When Brininess is A Tattle Tale

A dictionary definition of “fresh” is having its original properties unimpaired. Oysters destined for the raw, half-shell market are harvested alive, and properly stored so that they’re alive when opened. This is where an inquisitive nose does its job.

It doesn’t take much of a sniff. Odors in high concentration to the point of being unpleasant will let you know. Intense odors, especially pungent sulfur or rot, are reliable signs an oyster is no longer edible.

A Briny Bouquet of Freshness

Detecting separate whiffs of fruit, flowers, and canned corn with and without scientific instruments may play a viable role for researchers, ostreaphiles, ostreophiles, and marketeers. Perhaps the rest of us need only trust that the nose knows.