Oysters – All You Need to Know | Instacart’s Guide to Groceries

What are oysters?

Oysters are saltwater, bivalve mollusks that live in the ocean or other salty or brackish waters and play a vital role in our ecosystem. They are natural filter feeders that help to remove pollution from our oceans and create a clean underwater environment for other aquatic life. Individual oysters can filter up to 50gal of water a day and remove nitrogen, phosphates, and bacteria from the water.

Oysters are low in calories and high in micro-nutrients. Many types of oysters are considered a delicacy in some cuisines and are commonly eaten raw or cooked. 

Where did oysters originate from? 

The word “oyster” is derived from Latin and first appeared in English in the 14th century. It comes from the Old French word oistre. The ancient Romans practiced oyster farming commercially as early as the 1st century BC and later in Britain for export to Europe.

Oyster consumption grew in popularity as New York grew as a city, as the island of Manhattan was originally covered in bountiful oyster reefs when the first Dutch settlers arrived in the 17th century. By the 19th century, New York Harbor had become the largest source of oysters worldwide. 

Sadly, due to the mass destruction of the oyster beds, the abundance of native oysters in Manhattan was wiped out and never fully recovered despite rehabilitation attempts. 

How do oysters grow?

Naturally occurring oysters are tiny, free-swimming creatures when they’re born. Soon enough, they settle and attach in clusters to any solid surface—such as rocks, piers, or submerged items—which is where they usually grow and flourish for most of their lives.

As they grow in clusters, they fuse together and create rock-like oyster reefs that provide nurturing habitats for other marine species. Barnacles and mussels will settle on the oyster reefs, and these provide food sources for commercially valuable species of fresh fish such as:

• Silver perch
• Speckled trout
• Spanish mackerel
• Stone crab 
• Shrimp
• Blue crab

How do you harvest oysters?

There are set seasons for harvesting fresh oysters, so only harvest during legal seasons and check your local legislating body for the regulations on oyster harvesting. 

These guidelines are a good starting point if you want to collect them yourself:

1. Follow all your local department’s regulations and get a shellfish license to legally harvest oysters.
2. Have the right gear. You’ll need an oyster dredge, collection bucket, hammer, gloves, footwear, and ice.
3. Harvest at the right time. Traditionally, it’s recommended to only harvest oysters during the cooler winter months and not within the few days following heavy rainfall. Harvest in the daytime and at low tide for the best chances of accessing oyster reefs.
4. Either wade out to locate the oyster reefs or use a flat-bottomed oyster boat. Remove oysters from the reef by either raking your oyster dredge across the reef or using a hammer to knock oyster clusters off.
5. Use tools to separate individual oysters from their clusters. Remove any dead oysters and place any smaller oysters back in the water. Any live oysters with open shells will close their shells when tapped lightly.
6. Collect any edible, fresh oysters in a bucket of water, keep them cool, and stick to the collection limits.

What are the different varieties of oysters? 

There are over 200 species of oysters and hundreds of varieties of them. However, these varieties mostly originate from 5 popular oyster species: Pacific Oyster, Atlantic Oyster, Kumamoto Oyster, Olympia Oyster, and the European Flat Oyster. It’s these five that most commercially grown oysters come from.

Varieties of oysters are usually named after where they’ve grown or based on the location of the oyster bed, they hail from. 

Popular oyster varieties around the world include:

• Blue Point oysters from Long Island, U.S.
• Wellfleet oysters from Massachusetts, U.S.
• Malpeque oysters from Prince Edward Island, Canada
• Sydney Rock oysters, NSW, Australia 
• St. Helens oysters, Tasmania, Australia
• Coffin Bay King oysters, South Australia
• Bluff oysters, South Island, New Zealand
• Whitstable oysters, England, UK
• Belon oysters, France

What should I look for when buying oysters at the grocery store?

You’ll find fresh oysters in the seafood section of your grocery store. When shopping for fresh oysters, look out for shells that are tightly clamped shut or ones that shut when you tap them. Fresh means alive, and all bivalves in their shells—like oysters and mussels—have to be sold alive.

For ultimate freshness, ask your Instacart shopper to choose fresh oysters that are heavy and full of water which indicates they’re alive and fresh. 

If you are looking to have your groceries delivered, you can easily shop for fresh oysters via Instacart. After adding a product to your cart, use the “Instructions” option to notify your Instacart shopper about any preferences or specific directions on how to choose the best products. Shop for oysters.

How to store oysters

Fresh oysters must be alive before eating or cooking them. Ask your Instacart shopper to pack them in an open container covered with a damp cloth or a mesh bag, as fresh oysters won’t survive in an airtight container. 

When you’ve had your fresh oysters delivered, store them in the refrigerator, large shell-side down, for 5-10 days. Eat them within 24 hours of purchase for optimum flavor. 

How to tell if oysters are bad

Oysters that are bad will look dry, withered, and will be gray, black, or even pink in color. They will smell pungent or rotten, whereas fresh oysters will look plump, glossy, and smell fresh and mild. 

Oyster shells that do not open and are unresponsive are assumed dead and are therefore unsafe to eat or cook. Loose or broken shells mean the oysters have died and should be thrown out and never consumed.

Get fresh oysters delivered

Oysters are deliciously light and fresh and packed full of nutrients. Enjoy your fresh oysters on a half-shell paired with a crisp sauvignon blanc. Or maybe throw an oyster and champagne tasting party for the holiday season.

Whether you’re tipping them down the old-fashioned way with rock salt and lemon or garnishing them with a tasteful mignonette sauce, add fresh oysters to your shopping list and save time by ordering your grocery delivery with Instacart.

Grab it now on Instacart:

Live Mussels (1 lb)

Fresh Wild Caught Blue Crab (lb)

Blue Point Oysters (each)

Fresh Wellfleet Oysters (1 ct)

Fresh Malpeque Oysters (each)

Fresh Farm Raised Oysters in Shell (24 ct)

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Instacart is the leading grocery technology company in North America, partnering with more than 1,400 national, regional, and local retail banners to deliver from more than 80,000 stores across more than 14,000 cities in North America. To read more Instacart posts, you can browse the company blog or search by keyword using the search bar at the top of the page.