How to Dry Oregano: 4 Methods, Times and Temperatures

Of all the herbs you might dry, oregano is one of the most worth the trouble. America’s Test Kitchen lists it first among the herbs that work well dried,¹ and in ATK’s tests across 24 recipes, it was the one time tasters liked the dried herb better: dried oregano won in chili.² A dehydrator is the fastest reliable method, done in 1–4 hours. If you hang bundles instead, keep them small. The extension guides disagree on whether oregano is a sturdy herb that air-dries easily or a moist one that molds.

At a glance

Method	Settings from named sources	Time	Notes
Dehydrator	95–115°F, up to 125°F where humid³; Penn State says 95–110°F⁴	1–4 hours³	Most reliable
Air-drying	Small bundles hung at 70–80°F in a dry, ventilated spot out of direct sun⁵	Generally 2–4 weeks for sturdy herbs	Guides disagree on whether oregano counts as sturdy (below)
Oven	Lowest setting, not above 180°F, door open⁴	3–4 hours⁴	Or overnight with only the oven light on³
Microwave	On high, from 30 seconds to 3 minutes depending on the source (table below)	Minutes	Small batches only; paper towels can catch fire⁴
Sun	Not recommended		Costs color and flavor

Before you start

The extension guides agree on timing. Most herbs are best harvested for drying just before the flowers first open, picked early in the morning once the dew has dried. Oregon State adds that cut herbs shouldn’t lie in the sun or sit around after harvest.

Rinse the stems in cool water and shake off the excess, then pat off all the visible water with towels or paper towels. You’ll often read that rinsing rids herbs of pathogens. The extension guides call it cleaning and make no such claim.

Is oregano easy to air-dry? The guides disagree

Source	How it classes oregano	Advice that follows
National Center for Home Food Preservation³	With basil, tarragon, lemon balm and the mints: high moisture, will mold if not dried quickly	Dry fast, in small bunches or with a dehydrator
University of Tennessee⁶	The same high-moisture group	The same
University of Wisconsin⁵	With sage, thyme, rosemary and marjoram: sturdy herbs well suited to air-drying	Hang in bundles
Oregon State⁷	Not named	Not applicable

We haven’t picked a side. Tennessee’s wording closely follows NCHFP’s, so this is closer to one view against another than two against one, and none of the guides says it tested oregano. Play it safe and treat oregano as an herb that can mold. If your house is humid, use a dehydrator. If you air-dry, keep the bunches small and check them for mold.

Dehydrator

NCHFP says to preheat with the thermostat at 95–115°F, going as high as 125°F where it’s humid, and to expect 1–4 hours, checking now and then.³ Penn State’s range tops out lower, at 110°F.⁴ You’ll see a rule never to go above 125°F. That’s the top of NCHFP’s range, which it gives for humid conditions only. Spread the sprigs in a single layer and start checking at the one-hour mark.

Air-drying

The Wisconsin method for sturdy herbs: tie washed branches into small bundles of 5–6 stems and hang them upside down somewhere warm (70–80°F), dry and well ventilated, out of direct sun, until the moisture is gone. That’s generally 2–4 weeks.⁵ For herbs it treats as tender, Oregon State hangs small bunches inside a paper bag with vent holes cut in the top and sides, which usually takes 5–10 days.⁷ Either way, keep the bundles small. Bundles that are too big will mold, the University of Tennessee warns. You can also dry stripped leaves in a single layer on a screen or tray in a warm, dry room.

Keep drying herbs away from the sink, stove and dishwasher, where the air is moist, and NCHFP says drying indoors usually gives better color and flavor than drying outdoors.³ Oregon State suggests an attic, a kitchen or any warm spot with moving air. A paper bag punched with holes keeps dust off, and the Wisconsin guide says to pick one big enough that the leaves don’t touch the sides. You may read that a bag shields the leaves from light and so prevents discoloring. We found no source that says so, though the Wisconsin guide does say to dry out of direct sun.

Oven

Penn State’s method is the lowest temperature, not above 180°F, for 3 to 4 hours with the door open.⁴ The Wisconsin guide gives the same numbers, with the herbs in a single layer and stirred now and then. Drying herbs too hot can cost you flavor, Oregon State warns. Twenty minutes at 200°F gets passed around a lot, but it’s in none of the extension guides we checked.

If your oven can’t hold 180°F or lower, use the cool-oven method. Lay leaves on a paper towel so they don’t touch, cover with another towel and another layer of leaves, and repeat for up to five layers. Leave them overnight in an oven warmed only by the light of an electric oven or the pilot light of a gas one.³

Microwave

The microwave is fast, and it’s for small amounts only. The guides don’t agree on timing:

Source	Amount	Time on high	Method
Penn State⁴	Per cup	2–3 minutes	Start with 1 minute, mix every 30 seconds, keep checking
University of Tennessee⁶	Per cup	2–3 minutes	Start with 1 minute, mix every 30 seconds
Oregon State⁷	1 cup (never more than 1–2 cups)	1–2 minutes	Stir every 30 seconds after the first minute until almost dry, then finish at room temperature
University of Wisconsin⁵	4 or 5 branches between paper towels	2–3 minutes	Another 30 seconds if not brittle
America’s Test Kitchen¹	Not stated, on a paper towel	30–40 seconds	Crumble and store

Start with a minute or less, then check every 30 seconds until the leaves crumble.

Two safety points apply whatever timing you use. If the load is too small, the paper towels can catch fire, Penn State warns.⁴ And Oregon State says not to use paper towels made from recycled paper, which can contain metal scraps that arc.⁷ The Wisconsin guidance calls the microwave a last resort that cooks the herbs and gives very poor quality. It notes that the heat drives off some of the oils along with the water, so microwaved herbs may taste less intense than herbs dried other ways.⁵

Where the guides disagree

Question	What named sources say
Dehydrator temperature	95–115°F, up to 125°F where humidity is high (NCHFP, Tennessee, Oregon State)³⁷⁶; 95–110°F (Penn State)⁴
Air-drying time	Generally 2–4 weeks for sturdy herbs hung in bundles (Wisconsin)⁵; usually 5–10 days for tender herbs hung in small bunches inside bags (Oregon State)⁷
Microwave time	From 30–40 seconds (America’s Test Kitchen) to 2–3 minutes per cup (Penn State, Tennessee); see the table above
Oven	Lowest setting up to 180°F with the door open for 3–4 hours (Penn State, Wisconsin)⁴⁵; or no heat but the oven light or pilot light, overnight (NCHFP, Tennessee)³⁶

We didn’t find a side-by-side test of these on the same herb, so we haven’t picked a winner. Where you get a range, start low and check often.

What drying does to oregano

ATK’s tasters preferred fresh herbs in every use but one. The exception was chili, where dried oregano was the favorite. You’ll hear that drying “improves” oregano in general. The evidence is narrower than that: ATK found dried oregano did reasonably well in dishes cooked for more than 20 minutes with a good amount of liquid, and it won one test, in chili.²

How to tell it’s done

The herbs are dry when the leaves are crisp and crumble easily between your fingers and the stems break when you bend them. The leaves should also fall off the stems, Oregon State says. Strip the leaves and toss the stems.

Check again after you pack them. Wisconsin’s advice is to watch the filled containers for a couple of days. If you see any moisture, take the herbs out and dry them longer.⁵

Air-dried herbs can carry bugs. The University of Tennessee says air-dried herbs and seeds need treating to kill insects and their eggs, either by heating at 160°F for 30 minutes or by freezing at 0°F or lower for at least 48 hours. It recommends freezing for better flavor.⁶

Storing dried oregano

Keep the leaves whole and crumble them as you cook. Penn State says storing herbs whole is preferred. Use airtight containers somewhere cool, dry and dark, away from the stove and sink. Dried herbs can also go into airtight containers in the freezer, Oregon State adds.

How long dried oregano keeps depends on who you ask, and none of these numbers was measured on oregano:

Source	Scope	Figure
Penn State⁴	Most home-dried herbs	Keep well for up to a year
Oregon State⁷	Home-dried herbs	Up to one year; for best flavor, use within six months to a year
University of Wisconsin⁵	Home-dried herbs	Keep for years, but use within a year for best flavor
America’s Test Kitchen¹	Herbs dried in the microwave by its method	Up to 3 months, airtight
McCormick⁸	Leafy dried herbs, a spice company’s own guidance	1–3 years

They don’t agree, so we’ve left them side by side. McCormick defines shelf life as how long spices stay most aromatic, and that’s the right way to read every number here: a quality window, not a safety date. The real test is your nose. Crush a pinch, and if the smell is faint, the oregano has faded.

Herbs in oil are a separate food-safety question. A 2011 review of home-prepared vegetables and herbs stored in oil says to refrigerate them and use them within four days or throw them out, and calls freezing the safest option.⁹

Not yet measured

Whether oregano molds more readily than other herbs when air-dried; no guide we found tested it.
How long home-dried oregano keeps, measured on oregano rather than herbs in general.
Microwave times by oven wattage for oregano.

When You Should Actually Use Dried Herbs, America’s Test Kitchen. americastestkitchen.com · Publication ↩ ↩² ↩³
Science: Substituting Dried Herbs for Fresh, America’s Test Kitchen. americastestkitchen.com · Publication ↩ ↩²
Herbs (drying), National Center for Home Food Preservation. nchfp.uga.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹
Let’s Preserve: Drying Herbs, Penn State Extension. extension.psu.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹
Drying Herbs, Wisconsin Master Gardener Program, University of Wisconsin-Madison. mastergardener.extension.wisc.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹
Drying Herbs, University of Tennessee Extension. lawrence.tennessee.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵
Drying herbs (SP 50-921), Oregon State University Extension Service. extension.oregonstate.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷
How Long Do Spices Last?, McCormick. mccormick.com · Merchant ↩
Nummer et al., Food Protection Trends, 2011. foodprotection.org · Peer-reviewed ↩

Also drawn on

Preserving Herbs by Drying (Stacy Reed, updated 3 May 2024), Penn State Extension. extension.psu.edu

How to Dry Oregano: Methods, Temperatures and What Drying Changes