How to Dry Tarragon Without Losing Its Flavor: Low Heat, Fast Drying, and When to Freeze Instead

Tarragon is one of the harder herbs to dry well. Its flavor goes fast once the leaves are dried, University of Illinois Extension says.¹ Its leaves also hold a lot of water, so it can mold if it dries slowly.² Both problems have the same fix: dry it quickly, at low heat, and store it whole. And if it’s the flavor you’re after, freezing or a bottle of tarragon vinegar is worth a look.

At a glance

Which tarragon you have

The flavor worth drying belongs to French tarragon. The tarragon seed sold on racks and in catalogs is usually Russian tarragon, Illinois Extension notes, and it doesn’t have French tarragon’s smell or flavor.¹ French tarragon’s leaves taste of licorice or anise. For more on the plant and its types, see tarragon.

Harvest and prepare

• When. For most herbs, extension guidance says to harvest for drying just before the flowers first open, mid-morning after the dew has dried. PROSEA, writing about commercial growing, says leaves and tender tops can be harvested at intervals through the season.⁴
• Where to cut. Cut stems just above a leaf or a pair of leaves.
• Rinse. Rinse in cool water, shake off the excess, and toss bruised or damaged leaves.

Why low heat matters for tarragon

A 2007 study dried tarragon leaves at 45, 60 and 90°C and measured their essential oil over 120 days of storage.⁵

• Oil content dropped in storage no matter how the leaves were dried.
• Leaves dried at 90°C (194°F) changed most, losing about half their essential oil within 30 days.
• Drying at 45°C (113°F) caused the smallest quality changes.

PROSEA’s advice for commercial drying ends up in the same place: air-dry the shoots in the shade, or use dryers that stay at or below 43°C (109°F).⁴ Those numbers sit right at the top of the extension services’ dehydrator ranges below.

Dehydrator (best for tarragon)

• Temperature. The National Center for Home Food Preservation (NCHFP) says to preheat to 95 to 115°F, and up to 125°F where it’s humid.² Penn State says you can dry herbs in a dehydrator if it can be set between 95 and 110°F.³
• Time. NCHFP gives 1 to 4 hours. Check now and then.²
• Layout. Lay the sprigs on the trays so they don’t touch, in single layers with good airflow between trays.
• Afterward. Strip the dry leaves off the stems and store them whole (see storage below).

Air drying

Air drying is cheap but the least consistent method,⁶ and that matters more for tarragon than for sage or thyme. NCHFP lists tarragon among the high-moisture herbs that mold if they don’t dry quickly,² and Colorado State University Extension says to dry tender-leaf herbs like tarragon quickly, with its faster methods, to prevent mold.⁶

If you air dry anyway:

• Tie a few stems into a small bundle and hang it upside down by the tied end somewhere dry and well ventilated, away from the sink, stove or dishwasher.
• Keep it out of direct sun and heat, which fade flavor and color.
• Keep the bunches small. NCHFP’s paper-bag method warns that big bunches mold.² A paper bag punched with holes keeps dust off.
• Check it often, and throw out any bundle that molds.

Oven

Penn State generally doesn’t recommend the oven, because even the lowest temperature destroys much of the flavor. If you go ahead, its method is the lowest setting, no higher than 180°F (82°C), for 3 to 4 hours, with the door open.³ NCHFP suggests a very cool oven instead: the light of an electric oven or a gas pilot light can give enough heat to dry herbs overnight.²

You’ll often see instructions to set the oven to 250°F with the door open for an hour. We found no source for that temperature or time, and 250°F is well above both Penn State’s ceiling and the temperatures where the 2007 study saw tarragon lose oil.³⁵

Microwave

Microwaving is fast and fine for small amounts, but the published methods differ:

Penn State warns that paper towels can catch fire when there’s too little herb on them.³

How to tell when it’s dry

The leaves should be crispy and crumble easily, and the stems should break when you bend them. Dry them completely before you store them, or they can mold.³

Storing dried tarragon

• Keep the leaves whole until you cook. Whole dried herbs hold their flavor longer than crushed ones.
• Use an airtight container somewhere cool, dry and dark.
• Expect it to fade. Penn State says most dried herbs keep well for up to a year,³ and ATK gives up to 3 months for microwave-dried herbs.⁷ Neither number is specific to tarragon, and the 2007 study found tarragon’s oil dropping the whole time it was stored.⁵ Crush a leaf and smell it before you count on an older jar.

Cooking with home-dried tarragon

Dried tarragon won’t replace fresh where tarragon is the main flavor. The sources disagree on when to add it:

• ATK says to add dried herbs at the same point you’d add fresh.⁷
• Colorado State says to add dried herbs near the start of cooking, so they have time to rehydrate.⁶

We found no source that tests either approach with tarragon. For amounts and a fuller comparison, see dried tarragon vs fresh tarragon. For technique, see how to rehydrate herbs.

If you want the flavor, consider freezing or vinegar instead

Tarragon loses so much flavor when dried that a couple of other options are worth a look.

• Freezing. See can you freeze tarragon.
• Vinegar. PROSEA describes tarragon vinegar, made by adding the herb to wine vinegar,⁴ and Illinois Extension suggests tarragon for vinegars.¹
• Oil: be careful. Oregon State University Extension says homemade fresh or dried herbs in oil must be refrigerated and used within 4 days, or frozen, because of the botulism risk.⁸

Not yet measured

• How long tarragon takes to air dry at home, and how often it molds.
• How long home-dried tarragon keeps its flavor in a kitchen cupboard.
• How microwave drying compares with a dehydrator for tarragon.

Related

• Tarragon
• Dried tarragon vs fresh tarragon
• How to store tarragon
• Can you freeze tarragon?
• Tarragon uses
• Tarragon substitutes
• Too much tarragon
• Tarragon vs rosemary
• Tarragon vs thyme
• How to dry sage

Footnotes

1. Tarragon: French, University of Illinois Extension. extension.illinois.edu · Reference work ↩ ↩² ↩³

2. Herbs (Drying), National Center for Home Food Preservation. nchfp.uga.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

3. Let’s Preserve: Drying Herbs, Penn State Extension. extension.psu.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

4. Artemisia dracunculus (PROSEA), Plant Resources of South-East Asia. uses.plantnet-project.org · Reference work ↩ ↩² ↩³

5. Arabhosseini et al., Journal of Food Engineering, 2007 (abstract). agrar.uni-hohenheim.de · Peer-reviewed ↩ ↩² ↩³

6. Herbs: Preserving and Using, Fact Sheet 9.335, Colorado State University Extension. ccfruitandnuts.ucanr.edu · Reference work ↩ ↩² ↩³ ↩⁴

7. When You Should Actually Use Dried Herbs, America’s Test Kitchen. americastestkitchen.com · Publication ↩ ↩² ↩³

8. Herbs and vegetables in oil, SP 50-701, Oregon State University Extension Service. extension.oregonstate.edu · Reference work ↩

Also drawn on

• Dry Your Own Herbs and Spices (It’s Better Than the Jarred Stuff) (Lisa McManus, 26 Oct 2021), America's Test Kitchen. americastestkitchen.com