Can You Really Only Eat Oysters In "R" Months?

Many of us grew up hearing that it isn't safe to eat fresh oysters in months without an "R" in them, which is to say May, June, July, and August. Summer, in other words. Yet we see oysters year-round in markets and on menus, which begs the question of whether the old advice is still good advice.

The rationale behind skipping oysters during the warmest months was to avoid oysters that might not taste good or, even worse, be unsafe to eat. Back when we had only wild oysters, summertime was a factor on several fronts. Wild oysters spawn in the summer when the water is warmest. In many places, oyster season closed during that time period to give the oysters opportunity to reproduce, yielding a more generous and sustainable oyster harvest later in the year. Another factor is that spawning oysters are small, watery, and have unpleasant off-taste. No one wants to eat a flimsy, bitter oyster.

There were serious food safety issues to consider, as well. In the days before reliable refrigeration, we were wise to consider the risks of transporting raw seafood during the hottest months of the year. Bacteria and red tide algae levels in the water rise in summer as well. Eating shellfish that had absorbed these toxins could be poisonous to humans.

So, back in the day, the dire warnings to skip wild oysters during the heat of summer were warranted. But times, and oysters, have changed and it's okay to eat them year-round, if we prefer. The U.S. has made huge strides in the safe and sustainable harvesting of wild oysters. Oyster fishermen and various agencies monitor each step in the process, including water quality and safe transportation. By law, fresh oysters must be labelled with the time and place of harvest.

The popularity and availability of farmed oysters has surged, which means we're no longer reliant solely on wild oysters. Because some types of farmed oysters can thrive in conditions that are not hospitable for wild oysters, cold water farms can produce edible oysters year round. On farms in warmer waters, the oyster breeds are often triploids, which means they are sterile, similar to seedless fruits and vegetables. Oysters that never spawn cannot suffer the flavor and quality issues caused by summertime spawning.

Local oysters still usually have a peak season, but it's always oyster season somewhere, so we can source them from around the country and world. Oyster connoisseurs learn the differences among varieties harvested in various locations throughout the year, similar to an oenophile's knowledge of wine vintages.

No matter the month, no matter our level of expertise, the best advice is to buy oysters from reliable, reputable sources that take good care of them from the water all the way to our plates. The advice about the "R" months might no longer apply, but it will always be true that it's better to be safe than sorry when it comes to fresh oysters.