Chesapeake oyster merroir and the Tidewater roast

One oyster, eight waters

Every oyster on a Virginia table is Crassostrea virginica. What changes from one bed to the next is the water. Where a river empties into the bay, salinity falls toward 8 ppt and the oyster puts its energy into meat. Out on the seaside of the Eastern Shore the water is the open Atlantic at 32 ppt, and the oyster grows a deeper cup and a smaller, firmer, saltier meat. The wine trade calls this terroir. The oyster trade calls it merroir, and in Virginia the state marks out eight regions along the gradient.

The Society tastes them in order every closing Sunday, raw, starting fresh and finishing salt. The table below is how our stewards describe them, which is not an official text and should be read as the notes of people who have eaten a great many oysters standing on cold riverbanks.

The eight Virginia oyster regions, as the Society tastes them

Region	Salinity	Cup & meat	On the palate
1. Seaside, Eastern Shore (Chincoteague)	28–32 ppt	Deep narrow cup, firm small meat	Full ocean salt first, then a clean mineral finish. Eats fast off the sheet.
2. Bayside, Upper Eastern Shore	18–24 ppt	Medium cup, fuller meat	Salt softened by the bay, a little sweetness, grassy marsh note.
3. Upper Bay, Western Shore	10–16 ppt	Rounded cup, plump	Mild and buttery, little brine. Best stewed or roasted.
4. Middle Bay, Western Shore (Piankatank)	16–22 ppt	Even cup, balanced	Salt and sweet in balance, with a long buttery middle.
5. Lower Bay, Western Shore (Lynnhaven)	20–26 ppt	Large cup, full meat	Briny and rich. The oyster the colony sent to London.
6. Rappahannock River	8–14 ppt	Round cup, sweet plump meat	The sweet-brine oyster. Low salt, cream and a mild metallic edge.
7. York River & Mobjack Bay	18–22 ppt	Medium cup, firm	Mid-bay balance with a clean salt line and a crisp finish.
8. James River	8–12 ppt	Variable cup, soft plump meat	Fresh, sweet, almost nutty. The historic seed-oyster river.

Salinity moves with the season. After a wet spring the upper James can drop below 8 ppt for weeks; after a dry autumn a York oyster can taste almost like a bayside one. This is why the Society's provisioner on the almanac page asks which water your oysters come from before it tallies the bushels. Salt oysters run smaller in the cup and are eaten faster, and a roast that is a bushel short is a sorry thing.

The iron sheet and the wet burlap

The Tidewater roast is a cooking method, not a party, though it tends to become one. It needs four things: a fire of red oak burned down to embers, a sheet of plain iron plate laid across cinder blocks above the fire, a sack of oysters, and a burlap sack soaked in a bucket of water.

1. Burn the oak down first. Red oak is the Tidewater's roast wood because it is everywhere, splits clean and makes a long bed of hot embers without much flame. Light it at least an hour before the first oysters. You want coals, not fire, under the sheet.
2. Heat the sheet. A quarter-inch mild-steel plate, four feet by four, sits on blocks about eighteen inches above the coals. Flick water on it; it should dance off.
3. Lay the oysters in one layer, cup down. Half a bushel at a time, no more, so every shell touches iron.
4. Throw the wet burlap over. This is the whole trick. The burlap turns to steam, and the oysters cook in a cloud of their own liquor and river water from the sack. Add a splash from the bucket if the burlap dries.
5. Eight to twelve minutes. When the first shells start to gape, pull the burlap and shovel the oysters onto the table. Anyone with a glove and a knife is now the shucker. A gaper that has not opened in fifteen minutes goes in the gaper bucket, not down a throat.

A roast needs one sheet for every six or so bushels across an evening, with two burlap sacks a sheet so one is soaking while the other steams. The Society's rule for a standing roast is two dozen oysters a head, plus an eighth for gapers and mudders, rounded up to the half-bushel sack. A seated five-remove supper uses nine a head as a single course. For a cider-and-ham reception where oysters are a passing pleasure, six a head is generous.

What belongs beside a roasted oyster

Opinions on this get loud about an hour into any roast. The Society's position, set out in its 2015 founding minutes, is that a well-roasted oyster needs nothing. The second position, set out in the same minutes immediately below, is that the following are permitted on the condiment table and nothing else:

• Drawn butter in a tin kept at the edge of the sheet, with a spoon of its own.
• Hot vinegar sauce, which is cider vinegar warmed with black pepper, a little salt and a shaved shallot. This is the eighteenth-century table sauce for shellfish and the Society's own favourite.
• Grated fresh horseradish, not the jarred paste, which was being grown in Williamsburg gardens by the 1760s.
• Saltine crackers, which are not colonial, and which no one has ever managed to ban.
• A mignonette of Hewes Crab cider vinegar and shallot for the raw tasting only. On a roasted oyster it is wasted.

Bottled red cocktail sauce is tolerated on the grounds that guests bring it anyway. Lemons are sold in Williamsburg but were a luxury import in the 1750s, so the Society uses vinegar and leaves the lemons to the bar.

Oyster stew for the first remove

At the seated supper the oysters come as a stew rather than from the sheet, because a long table under candles is no place for a shucking knife. The receipt is Mary Randolph's from The Virginia House-Wife of 1824, which is itself a Tidewater kitchen's habit written down: a pint of shucked Rappahannock oysters with their liquor, a pint of cream, a knob of butter, white pepper, a blade of mace and a grating of nutmeg, warmed until the edges of the oysters curl and not a moment longer. Served with Sally Lunn bread and a dry Albemarle Pippin cider, it is the best first course the colony ever produced.

The season and the beds

Virginia's wild oyster harvest runs from October to March in most waters, which is why the Society's festival sits in November and why the old saying about months with an R in them still has some truth to it. Aquaculture oysters, grown in cages and floats on leased bottom, are harvested year-round and are what most restaurants serve. The Society buys both: wild James River oysters by the bushel for the opening roast, because that is the historic river and the historic method, and cage-grown oysters from a named lease for the raw tasting, because a raw oyster should come from a bed you can point to on a chart.

Wherever you buy, ask for the harvest tag that must travel with every sack. It tells you the water, the date and the dealer. An oyster roast begins with a tag, not a fire.