Raw fish-based dishes, like sushi and ceviche, are quite popular. With home cooks becoming more adventurous and preparing these dishes in their own kitchens, it's important to know the answer to the question: Is raw fish actually safe to eat? And if so, when?
Understand There Is Always Risk
Not to dissuade you from consuming raw fish, but Harold McGee said it best when he wrote: "All uncooked fresh fish pose the risk of carrying a number of microbes and parasites that can cause food poisoning or infection." There is always a risk, whether you are consuming completely raw sushi or even ceviche.
Ceviche is marinated in citrus juice, which does "cook" the outside of the fish, but depending on how long you let the fish sit for, that marinade might not penetrate all the way through. In fact, at this time, there aren't any guidelines from the U.S. Food and Drug Administration specifically addressing ceviche, or whether marinating fish in acid is effective at killing parasites.
To minimize risk, you should invest in the best fish from a reliable fishmonger who understands that the fish is to be consumed raw. Talk to your fishmonger so you can make an informed decision.
The Safest Raw Fish: Fish That Has Been Frozen
I know this seems a little backwards because we often hear "fresh is best," but in this case, that's not entirely true. Of course, you have to source the freshest fish from a trustworthy source, but more importantly, if the fish is to be consumed raw, your fishmonger must sell you a fish that was previously frozen to kill off any parasites.
Simple refrigeration is not a good method of controlling parasites; those parasites come from an aquatic environment and may thrive at refrigerator temperature since the temperature of a fridge may be as cold as the environment they come from. Basically, refrigeration represents a happy temperature for these organisms to reproduce. Yikes!
FDA guidelines state that prior to consuming raw fish, the fish must be frozen at specific temperatures and stored frozen for a certain period in order to effectively kill parasites. These are the recommendations from the FDA for proper freezing of fish that will be consumed raw. The fish must be:
- Frozen and stored at a temperature of -20°C (-4°F) or below for a minimum of 168 hours (7 days) in a freezer; or
- Frozen at -35°C (-31°F) or below until solid and stored at -35°C (-31°F) or below for a minimum of 15 hours; or
- Frozen at -35°C (-31°F) or below until solid and stored at -20°C (-4°F) or below for a minimum of 24 hours.
The moral of the story is that you should not banish raw fish from your menu planning, but you must be careful and shop wisely.
Do you make your own sushi or ceviche at home? What precautionary steps do you take when you are preparing raw fish-based dishes?