The Perfect Ceviche, Explained By Science

The first time I tried ceviche was at a Peruvian restaurant in Miami on the insistence of my Peruvian taxi driver. Instead of taking me to my hotel, as requested, he delivered me to a hole-in-the-wall lunch spot. (I didn’t put up much of a fight!) On a Formica table covered with a clear plastic tablecloth, ceviche became my new obsession. The fish was silky and cold, firmed up by lime juice. Red onion added a juicy crunch, while the citrus hit was so bright it made my tongue tingle. 

I’ve since had many iterations in Mexico, with raw tuna or chargrilled octopus drenched in tangy lime juice and piled high on hot, crispy tostadas, and in Hawaii, where Japanese culinary influence introduced soy sauce and sesame oil to the mix. 

Ceviche is made by marinating raw fish or seafood in citrus juice, which gives the protein a firm texture without using heat.

Many people think that the acid “cooks” the fish. In reality, acid doesn’t cook anything; it denatures the proteins, turning the seafood opaque and firm, similar to what happens when it’s cooked. The difference is that heat unravels proteins in a way that causes them to bind tightly together, while acid keeps them more loosely connected, preserving a silkier texture. And that’s what I love about this method—the fish remains buttery-soft and delicate. 

Timing matters: a brief marination of about 10 minutes keeps the fish tender. After 15 minutes, it can turn rubbery or mushy as the acid continues to break down the proteins. 

Citrus doesn’t kill bacteria the way heat does, so using sushi-grade fish is key for food safety. You can find it in the freezer section of most grocery stores, where it’s often labelled as sashimi.

While traditional ceviche is made with fish or seafood, I also love plant-based versions that mimic the texture and bright flavours using ingredients like hearts of palm and avocado. Every style is delicious, especially if you can work in a little extra seasoning from a warm ocean breeze. 

Quick Tuna Ceviche

Fresh, bright and packed with flavour, this tuna ceviche comes together in minutes. The citrus cures the fish just enough to keep it tender while still letting the bold flavours shine. Serve with tortilla chips, tostadas or cucumber slices. Get this quick tuna ceviche recipe.

Vegan Ceviche

Hearts of palm have a naturally flaky, tender texture that reminds me of a cross between cooked baby potatoes and artichoke hearts. They work really well as a substitute for seafood. One note: They’re often packed with citric acid, which can make them extra tangy—avocado adds creaminess to balance this tartness. Get this vegan ceviche recipe.