The triploid may taste better in summer, but some fear that it's still no safeguard from warm-water bacteria. (Tim Carman/The Washington Post)

Dan Grosse, a partner with the Toby Island Bay Oyster in Chincoteague, Va., says it is his company’s policy not to put its oysters on the market from about mid-June to mid-September, when water temperatures rise above 75 degrees. It’s a safety issue for Grosse and his team. Warmer waters are a breeding ground for bacteria such as Vibrio vulnificus, which occurs naturally but, as the Food and Drug Administration points out, can be “found in higher concentrations in the summer months as water becomes warmer.”

“Because the waters are warmer, the health risk is increased,” says Grosse. “It’s not a big increase, and it’s not a big risk.”

Andy and Jill Buck, owners of Patuxent Seafood, hope their triploid oysters create a summer market for them. (Tim Carman/The Washington Post)

Triploids, as the oyster’s inventor Stan Allen indicated on today’s Free Range chat, are not immune to Vibrio. “[T]hey are prone to the same environmental issues, such as Vibrio and harmful algal blooms, that anything living in the water would be,” he wrote. “Sterility plays no role here.”

Besides, Grosse says triploids lose some flavor during the warm months, even though the oysters don’t reproduce. “I find that they don’t taste as good in mid-summer as they do in cooler months,” says Grosse who grows triploids at Toby Island Bay. He acknowledges that the flavor loss isn’t as great, however, as with diploids.

Even Woodberry Kitchen chef Spike Gjerde, a major supporter of Chesapeake oysters, refuses to sell them from Memorial Day through Labor Day. Like with Grosse, Gjerde says the profit of selling oysters in summer is not worth the risk of harming someone — or your own reputation.

The chef says that during the hot months, there are just too many opportunities for oysters to go bad, including harvesting and handling. “It’s just my gut,” he says. “It’s my gut that’s saying, ‘Let’s give it a rest in the summer.’ ”

Further reading:

* In Spike Gjerde’s world

* It’s August. Have an oyster.

* Oyster vs. oyster