Cooking With Basil: When to Add It, How to Cut It and Which Basil to Use

Basil gone black on the cutting board, or flat and grassy in the sauce? Both are easy to fix: add basil late, chop it last, and pick the right basil for the dish. Its aroma is fragile and heat drives it off; in a Thai stir-fry, holy basil gets about 15 seconds in the wok. And the old rule that torn basil beats chopped didn’t hold up when America’s Test Kitchen put it to a taste test. For the plant itself and its chemistry, see the basil profile.

At a glance

Choose the right basil

The basil in most Western supermarkets is sweet basil, the one for pizzas, pasta, chicken and cheese dishes, and pesto. Two Asian basils are worth knowing:

• Thai basil is a form of the same species, sold under the Thai name horapha. Sherri Pengjad of Thai Foodie describes it as sturdier than Italian basil and better able to hold up in hot dishes.⁶ See Thai basil.
• Holy basil (bai kaphrao in Thai, tulsi in Indian grocery stores) is the basil in phat kaphrao, the Thai stir-fry. Pad kra pao literally means “holy basil stir fry.” See holy basil.

Swapping them. Pailin Chongchitnant of Hot Thai Kitchen prefers Italian basil as the substitute when holy basil is unavailable, and says Thai basil also works.⁷ So the basils can cover for one another, though Thai Foodie notes the dish will taste less traditional.⁶ Sweet basil is also an important ingredient of Thai cuisine,⁸ so “Thai food means Thai basil” is a simplification. Use the recipe’s basil when you can. See basil vs. Thai basil and Thai basil vs. holy basil.

Add it late

Delicate herbs, basil included, tend to be more volatile than hearty ones, and long cooking can cost them flavor and aroma. Sturdier herbs like oregano, rosemary and thyme go in earlier. That’s why basil goes in late. How late depends on who you ask:

Part of the disagreement is scope: LSU’s advice is aimed at basil, Delaware’s at herbs as a group. For basil in a long-cooked sauce, you can split the difference: add some early for background and a handful at the end for aroma.

Chop it, and chop it last

Tearing versus chopping. You’ll often hear that torn basil tastes better than cut. America’s Test Kitchen tested this in a quick tomato sauce with basil and a black bean salad with cilantro: tasters slightly preferred the chopped herbs, which spread more evenly through the dish, while big torn pieces could taste overwhelming. Its conclusion is to chop herbs for flavor throughout a dish.³

Blackening. Freshly chopped basil darkens quickly through oxidation, and ATK notes that the color change doesn’t hurt its flavor.⁴ ATK tried several ways to keep it green. Blanching in boiling water kept the leaves bright green but was too much work for a garnish, so its advice is to chop basil and add it just before serving.⁴ The knife isn’t the problem. Time is. (Blackened leaves in the refrigerator are a different problem, chilling injury; see Storage below.)

Pesto

In pesto, basil is the star. In Samin Nosrat’s mortar-and-pestle version, adapted from Lidia Caveri, packed basil leaves (preferably Genovese) are the largest ingredient by far, with smaller amounts of pine nuts, a single clove of garlic, Parmigiano-Reggiano and pecorino, loosened with extra-virgin olive oil. She pounds the pine nuts to a paste first, then adds the basil with a pinch of salt, which she says helps break down the leaves. The recipe dresses 1 pound of trofie or spaghetti, and leftovers go under a layer of olive oil in the refrigerator for up to 2 days.¹⁰

Bitter pesto. Tasting Table points to two basil-related causes: blending the leaves too long can bruise them and release bitter compounds, and mature or damaged leaves tend to taste more bitter than young ones.¹¹ If you use a blender or food processor, pulse it briefly. See Genovese basil for the cultivar most pesto recipes call for.

Thai stir-fries

In Andy Ricker’s kai kaphrao, the holy basil is stirred in only until it wilts and smells fragrant, about 15 seconds. Thai Foodie describes Thai basil as stirred in right before serving.⁶ Same add-it-late rule, just squeezed into a much hotter, faster dish. Hot Thai Kitchen’s pad kra pao uses 1 1/4 cups of holy basil or regular basil leaves.⁷

Dried basil

Think of dried basil as a different ingredient, not a weaker copy of fresh:

• Britannica describes dried basil leaves as less fragrant and more pungent than fresh.¹²
• America’s Test Kitchen lists basil among the herbs that are better fresh, because delicate herbs are much weaker in flavor once dried.¹³
• In ATK’s testing, dried herbs held up best in recipes with fairly long cooking times (more than 20 minutes) and a good amount of liquid.⁵

So use dried basil in soups, braises and slow tomato sauces, and fresh basil where it’s the point of the dish.

Ratio (Computed): For converting, LSU AgCenter’s rule is 1 tablespoon of finely cut fresh herbs to 1 teaspoon of crumbled dried;¹ ATK’s tests found 1 part dried to 3 parts fresh came closest.⁵ Both work out to the same 1:3. See dried basil vs. fresh.

How much to use

Ratio (Attributed): The University of Delaware groups basil with the medium-strength herbs and suggests 1 to 2 teaspoons for six servings as a moderate amount.² That’s a general starting point for the herb group, not a basil test, and it doesn’t fit dishes like pesto, where basil makes up most of the sauce. Taste and add more at the end.

Buying in season

Basil is extremely frost-sensitive, so it’s a summer herb in temperate gardens. You’ll hear that off-season basil costs more and tastes worse; we found no price data to confirm it. Limp, wilted leaves have lost the aroma you’re buying basil for, so pick perky ones.

Storage, briefly

Rutgers Cooperative Extension puts the best storage temperature for fresh basil at 55°F, and notes that colder storage causes chilling injury, with blackened leaves and loss of aroma. Keeping the stems in water can reduce water loss.¹⁴ For freezing, Penn State Extension describes filling an ice cube tray half full of water and adding about a tablespoon of herbs to each section; frozen herbs go into cooked dishes without thawing and are generally not attractive as garnishes.¹⁵ Full guides: how to store basil, can you freeze basil? and how to dry basil.

Safety

Basil contains estragole. Germany’s Federal Institute for Risk Assessment (BfR) says estragole and related compounds are mutagenic and carcinogenic in animal studies, and names basil-containing pesto among foods that may contain high amounts.¹⁶ That evidence comes from animal studies and exposure estimates, not from people eating basil. See the basil profile for the regulatory history. If a dish has too much basil, see too much basil.

Related

• Basil, the full profile, and basil uses
• Thai basil, holy basil, Genovese basil
• Basil vs. oregano, basil vs. Thai basil
• Thai basil substitutes