Italian (Sweet) Basil vs. Thai Basil: What’s the Difference?

A third of my tiny windowsill herb garden is devoted to growing various types of basil. Even when I’m not cooking with the herbs, I often rub their fresh leaves between my fingers to release their powerful aromas, which range from sweet to peppery. Some varieties, like holy basil, have a dank, musky smell reminiscent of marijuana.

Do I need multiple basil varieties in my kitchen? I certainly think so, but even if you don’t want to devote time and space cultivating your own, it’s worth knowing when to use the two most common types of sweet basil and why. Most commercially grown basil in the U.S. comes from Hawaii, where an estimated 60% of the 12 million-pound annual harvest is sweet Italian basil, the most popular variety in western supermarkets. Hop over to an Asian supermarket, and sweet Thai basil, which accounts for the remaining 40% of the crop, reigns supreme.

To learn about the differences between the two basil varieties, I spoke with Ann Ziata, a chef at the Institute of Culinary Education’s New York City campus, and Jet Tila, chef and author of 101 Thai Dishes You Need to Cook Before You Die.

What’s the Difference Between Italian (Sweet) Basil and Thai Basil?

Sweet basil (Ocimum basilicum) is native to India and Asia and is a part of the Lamiaceae family, which includes mint. The herb grows quickly and easily in warm, sunny weather, and thrives equally well in gardens and containers. Like most edible plants, their flavors vary depending on the variety. Ziata tells me that while Thai basil and Italian basil are both sweet basils that share similar characteristics, they’re still very different herbs.

Italian basil (a.k.a. sweet basil)  is lightly sweet with a hint of black pepper. The leaves are wide, with some large enough to fit in the palm of your hand, but they’re also thinner and more delicate than Thai basil leaves, and are prone to bruising. This type of basil is used widely in the Mediterranean, where it features heavily in Italian, Provençal, Greek, Turkish, and Lebanese cuisines.

Thai basil has a strong, savory licorice flavor. It has purple stems and smaller, narrower green leaves that are thick and hold up well during cooking. It’s an integral ingredient to Southeast Asian cuisines, such as Thai, Vietnamese, Laotian, Cambodian.

What Are the Best Uses for Italian (Sweet) Basil vs. Thai Basil?

“Both go heavenly with summer vegetables like eggplant, peppers, and yellow squash,” says Ziata. (Provençal ratatouille, anyone?) She recommends pairing Thai basil with coconut, galangal, ginger, lemongrass, scallions, and cilantro, and notes that Italian basil goes particularly well with oregano, balsamic, lemon, pine nuts, olives, and soft cheeses.

Ziata says Italian basil’s rounded flavor is the ultimate sidekick to tomatoes and mozzarella—fresh in a caprese, simmered in tomato sauce, or scattered atop Neapolitan pizza. A particularly well-known cultivar from Italy is Genovese basil, which is famous for its use in pesto alla Genovese; it also goes wonderfully with garlic and white beans.

Because Italian basil is very delicate and will wilt quickly when cut or cooked, it’s generally sliced or torn into pieces, then added towards the end of cooking. Thai basil, on the other hand, is a much sturdier herb that can withstand the heat of cooking without compromising texture or appearance.

Thai basil’s resilience is matched with a pungent, aromatic flavor that goes well with other bold ingredients, says Ziata, who enjoys using the herb in a stir-fry with ginger, garlic, and chilies.

There are two main ways to enjoy Thai basil, says Tila. “It’s either dropped into hot dishes, like pad kee mao, curries, or pho, where the essential oils permeate the dish, or it’s eaten raw in a salad or parcel, like gỏi cuốn (summer rolls), for a burst of herbaceousness.”

Tila also recommends using the purple flowers of the Thai basil if they’re still attached to your stems. “They look nice on a fresh Vietnamese rice paper roll platter or as a garnish,” he says. “And they taste like concentrated Thai basil, especially that anise flavor, with a little more bitterness.”

Ziata says both basils are also fantastic herbs to pair with summer fruits like strawberries and peaches. To add a burst of refreshing, herbaceous flavor to desserts like strawberry sorbet or peach melba, top them with a chiffonade of fresh basil. 

Can You Substitute Italian (Sweet) Basil for Thai Basil, and Vice Versa?

If you can’t get your hands on Thai basil, Tila says you can use Italian basil, but the dish will lack that distinctive licorice kick: “Italian basil still offers a mild anise note, and I would rather somebody get part-way there than just throw up their hands and not make the recipe.”

Conversely, using Thai basil in place of Italian basil may be too jarring, as Thai cuisine often has the bold flavors of fish sauce, chiles, and acid to help balance Thai basil’s robustness, says Tila. Italian food, on the other hand, has tomato, cheese, salt, and a little acid—mellow ingredients that would likely be overpowered by Thai basil.

“I personally do not recommend substituting one for the other,” says Ziata. “They are both very unique and have differing flavors, textures, and intensities.”

The Takeaway

While both Italian and Thai basil bring unique flavors to the kitchen, they are best suited for different culinary applications. Italian basil, with its mild and sweet notes, is a staple in Mediterranean dishes—ideal for fresh caprese salads, pesto, and pasta sauces. On the other hand, Thai basil, with its robust anise and licorice flavors, shines in Southeast Asian cuisines, and is perfect for stir-fries, curries, and pho. 

While substitutions can be made in a pinch, the distinctive characteristics of each type of basil make them irreplaceable in their respective culinary contexts. For the best results, seek out fresh Thai basil when your recipe calls for it, but don’t hesitate to experiment and adjust seasonings if you must substitute.