Fresh Oregano vs. Dried: One of the Few Herbs That Dries Well

Oregano is one of the herbs America’s Test Kitchen found holds up well dried, unlike basil or parsley.¹ Fresh and dried are the same herb, mostly Origanum vulgare and its close relatives in the mint family. Use 1 teaspoon of dried for every tablespoon of fresh; dried is about three times as strong by volume. Fresh gives you a greener, softer flavor and its color, while dried is the easy choice for long-cooked dishes. Dried is also where the quality problems pile up: in EU testing, 48% of oregano samples were suspected of adulteration, mostly with olive leaves.²

Side by side

For the plant, its chemistry and its history, see oregano.

What drying does to oregano

Oregano’s bite comes from phenols in its essential oil. A 2020 review puts carvacrol and thymol at about 78 to 85 percent of oregano oil.⁴

A 2022 Italian study dried oregano several ways (in shade, in a static oven, with three microwave treatments and with an osmotic treatment) and compared the oils with oil from the fresh plant.⁵

• Carvacrol was the main compound in every sample, at 56.2 to 81.4% of the oil.⁵
• After drying, the shares of carvacrol, isoborneol and linalool rose significantly, while p-cymene, γ-terpinene and α-pinene fell.
• Oil yields and makeup varied with the drying method; microwave and shade drying gave the highest yields.

Those are percentages of the oil, not amounts in a teaspoon, and the study didn’t run a taste test. They fit what ATK found in the kitchen: dried oregano, rosemary, sage and thyme did reasonably well in dishes with fairly long cooking times (more than 20 minutes) and a good amount of liquid.¹ ATK’s Danielle Lapierre lists oregano first among the herbs worth using dried.⁷

How much to use

Ratio (Computed): The sources agree on about 1 part dried to 3 parts fresh.

Ratio (Disputed), ground oregano: NDSU and Penn State disagree twofold on how much ground herb equals a tablespoon of fresh, and neither says how it got its figure.¹⁰¹¹ Start with 1/4 teaspoon ground per tablespoon of fresh and taste.

Delaware’s guide suggests crushing dried herbs first to release some of their oils. Rubbing dried oregano between your palms as it goes into the pot does the same thing.

When to use each

Dried oregano is the default for cooked dishes. Oregano is essential in Italian pizza and pasta sauces, Greek salads and gyros, and dried oregano does well in sauces and braises that simmer.¹ ATK groups oregano with the hearty herbs that go in early, and LSU AgCenter puts it among the less delicate herbs. The University of Delaware rates oregano a medium-strength herb, not a dominant one, with a starting amount of 1 to 2 teaspoons for six servings.¹³

Fresh oregano shines where the leaves stay visible or barely cooked: scattered over pizza or roasted vegetables after cooking, chopped into salsa verde or a Greek salad, or steeped in olive oil. Even with oregano, ATK’s tasters preferred fresh herbs to dried in all but one use.¹

Mexican oregano is a different plant. Most “Mexican oregano” is Lippia, in a different family, Verbenaceae. ATK found it stronger than the Mediterranean kind, with a hint of menthol.¹⁴ It’s sold almost entirely dried, so swapping fresh for dried rarely comes up. See Mexican oregano vs. oregano.

Buying dried oregano

Dried oregano is where the quality problems pile up. In the European Commission’s 2019–2021 coordinated control plan on herb and spice fraud, 48% of oregano samples were suspected of adulteration, mostly with olive leaves.² An international Codex standard sets quality requirements for dried oregano.³ Whole or crushed leaf makes foreign leaves easier to spot than fine powder does. With fresh oregano, what you see is what you get.

The EU’s pyrrolizidine alkaloid limit for dried oregano, 1,000 µg/kg, is also higher than the 400 µg/kg allowed for most other dried herbs.⁶

Can one stand in for the other?

Yes, either way, and more easily than with most herbs.

• Dried for fresh. Ratio (Computed): 1 teaspoon dried per tablespoon of fresh. Best in anything that simmers; weakest as a raw garnish.
• Fresh for dried. Ratio (Computed): 1 tablespoon fresh per teaspoon of dried. Add it a little later than you’d add dried.

If you have neither, oregano substitutes ranks marjoram, thyme, basil and others by the job oregano is doing.

What isn’t known

• Beyond ATK’s general herb tests, we found no study comparing fresh and dried oregano in the same dish.
• The 2022 drying study reports oil makeup, not flavor, and its abstract doesn’t give oil yields for fresh versus dried material.⁵
• We found no shelf-life figure for dried oregano from a regulator or standards body.
• You’ll often read that fresh oregano is healthier than dried. We found no source comparing the nutrients in the two at the amounts cooks use.

Related

• Dried herbs vs. fresh: the general rules for every herb.
• Oregano, oregano substitutes, oregano uses and cooking with oregano
• How to dry oregano, can you freeze oregano? and too much oregano?
• Marjoram vs. oregano, oregano vs. thyme and Mexican oregano vs. oregano
• Dried rosemary vs. fresh, fresh thyme vs. dried and fresh sage vs. dried sage: the other hardy herbs.