Italian Parsley vs. Curly Parsley: Flavor, Chemistry and When It Matters

Does it matter which parsley you buy? Less than you might think. Italian (flat-leaf) and curly parsley are the same species, Petroselinum crispum, in two leaf forms, and flat-leaf has the stronger flavor. In a blind test by America’s Test Kitchen, tasters couldn’t tell the two apart in croutons that used a little parsley, but strongly preferred flat-leaf in tabbouleh and salsa verde.¹ Curly parsley isn’t flavorless, though, and it holds its own as a garnish.

Side by side

The chemistry rows come from one reference and one set of samples, so they show how the two types can differ, not what’s in any bunch at the store. They also show that “stronger flavored” doesn’t just mean “more oil”: PROSEA gives curly parsley the higher oil content and flat-leaf the stronger flavor.² We found no source that explains the gap. For the plant in depth, see our parsley profile.

The names

“Italian parsley” and “flat-leaf parsley” are two names for one herb. The Royal Horticultural Society lists flat-leaved, Italian and plain-leaved parsley as common names for the same plant, and the University of Maryland Extension captions it “Italian or flat-leaf parsley.” PROSEA files var. neapolitanum, “or Italian parsley,” in its flat-leaved group, alongside cultivars sold as ‘Plain’ and ‘Plain Italian Dark Green’. See flat-leaf vs. Italian parsley.

PROSEA also recognizes a third cultivated group, turnip-rooted or Hamburg parsley, grown for its root, not its leaves.

What a blind tasting found

America’s Test Kitchen chopped both types so finely they looked alike, then used each in three of its recipes: tabbouleh, salsa verde and herbed croutons.¹ The results:

• Herbed croutons. The recipe uses only a little parsley, and tasters couldn’t tell the difference.
• Tabbouleh and salsa verde. Here parsley is a major ingredient, and tasters strongly preferred the flat-leaf versions, calling them fresh and vibrant with a lemon-pepper astringency. The curly versions came across as mild and vegetal.

ATK’s takeaway: if you’re just sprinkling a little chopped parsley over a dish for color, either one’s fine, but if parsley is a major player, use flat-leaf. It adds that flat-leaf is easier to chop than curly.¹

That lines up with flat-leaved parsley being the stronger-flavored type. It doesn’t mean curly parsley is tasteless. Curly parsley’s fresh leaves are used for seasoning as well as garnish.

Differences that change the dish

Parsley as the main event. In tabbouleh and salsa verde, flat-leaf gave the brighter result in ATK’s test.¹ By the same logic, we’d pick it for chimichurri, gremolata or a parsley sauce. Its flat leaves also look a lot like cilantro (Healthline points this out when it suggests cilantro as a garnish swap for flat-leaf parsley), so label your bunches.

Parsley as a garnish. Garnishing is an old job for parsley. The ancient Greeks and Romans used the leaves as a flavoring and garnish. Curly parsley’s ruffled leaves add volume and color on the plate, and its milder flavor won’t fight the dish. When a garnish is just a light sprinkle, ATK’s crouton test suggests your choice won’t change the taste.¹

In cooking. Parsley belongs with the delicate herbs best added in the last minute or two of cooking, since long heat costs flavor and aroma. That goes for both types.

Can one stand in for the other?

Yes, though the dish will taste a bit different where parsley is a main flavor. The amounts below are starting points, same as on our flat-leaf vs. Italian parsley page.

• Curly for Italian. Ratio (Method): Use the same amount. If parsley is a main ingredient, as in tabbouleh or salsa verde, taste and add more, and chop it finely. You’ll see a rule of using twice as much curly parsley, but we found no source for it.
• Italian for curly. Ratio (Method): Use the same amount. Chopped finely, flat-leaf works fine as a garnish, and its stronger flavor is rarely a drawback.
• Dried for fresh. See fresh vs. dried parsley and parsley substitutes for the attributed dried-to-fresh conversion and other ranked options.

What isn’t known

• Why flat-leaf parsley tastes stronger despite PROSEA’s lower oil figure. We found no source that explains it.
• The chemistry comes from a single set of German-grown samples. We found no retail survey comparing the two types.
• We couldn’t trace the popular claims that curly parsley holds up longer after chopping, turns bitter with age, or is what French recipes mean by “parsley.”
• The ATK result comes from one tasting with three recipes.

Safety

Cooking amounts of parsley leaf aren’t a concern for most people. MedlinePlus lists parsley among foods that can change how the blood thinner warfarin works. Its advice isn’t to avoid them, but to keep the amount steady from day to day.³ Our parsley profile covers seed oil and other concentrated preparations, which are a different matter.

Related

• Parsley profile and flat-leaf vs. Italian parsley
• Parsley substitutes and fresh vs. dried parsley
• Cilantro vs. parsley, chervil vs. parsley, basil vs. parsley
• How to store parsley, too much parsley, fines herbes