Can You Freeze Thyme? | SPICEography

Yes, thyme freezes well. Ohio State University Extension describes freezing as the method used for hearty herbs such as thyme and rosemary,¹ Penn State Extension notes that thyme can be frozen right on the stem,² and America’s Test Kitchen names thyme among the sturdy herbs that work best for herb ice cubes.³ For the best quality, Ohio State advises using frozen herbs within 3 to 6 months.¹

There is also some lab evidence. In a nine-month storage study, frozen thyme lost the least essential oil of three preservation methods, and air-dried thyme lost the most.⁴

At a glance

Question	Short answer
Can it be frozen?	Yes, as sprigs or as leaves.²
Best methods	Sprigs tray-frozen then bagged; washed sprigs straight into freezer bags; or chopped leaves in ice cube trays under water or oil.⁵³⁶
Blanch first?	No source recommends blanching thyme.
Freezer temperature	0°F or below.¹⁵
How long	For best quality, 3 to 6 months (Ohio State). Other figures below.
Thaw first?	No. Add it frozen to cooked dishes.²
Oil cubes	Keep them frozen; once thawed, refrigerate and use within 4 days.⁷

How to freeze thyme

Prepare it. Rinse the sprigs, then pat or spin them dry.² Freeze thyme at its peak freshness.¹ You can leave the leaves on the stems; Penn State says thyme can be frozen on the stem.² Frozen leaves rub off the stems easily, which is common practice rather than a sourced claim.

About blanching. Some guides tell you to blanch thyme for a minute before freezing. We found no source that recommends it. Penn State mentions blanching only for larger herbs such as basil, for 15 seconds.² The USDA freezing fact sheet describes blanching as a step for vegetables, whose enzymes freezing only slows.⁸

Method 1: bag the sprigs. Put washed herbs in airtight freezer bags and freeze them.⁶ Press out as much air as possible before sealing;⁵ air reaching the surface of frozen food is what causes freezer burn.⁸ Sprigs bagged this way can freeze into a clump, so use small bags (editorial).

Method 2: tray-freeze. Spread well-drained sprigs in a single layer on a tray, freeze until firm, then move them to labeled bags or containers.⁵ They stay separate, so you can take out one sprig at a time.

Method 3: ice cubes. America’s Test Kitchen chops the herbs, puts 2 tablespoons in each well of an ice cube tray, covers them with water or oil, freezes them, then stores the cubes in a zipper-lock freezer bag.³ ATK suggests oil cubes when they will start a sauté and water cubes for pan sauces, soups and stews.³ Herbs frozen in oil keep their color better than herbs frozen on their own, though herbs in cubes cook unevenly as the cube melts.²

Method 4: thyme butter. Mixing chopped thyme into softened butter, rolling it into a log in plastic wrap and freezing it, then slicing off what you need, is a common kitchen practice. We found no extension or regulatory guidance on freezing herb butter, so we can’t give a storage time. Keep it frozen, and refrigerate any portion you thaw (editorial).

Label and date everything.²¹ Penn State suggests double-wrapping strong-smelling herbs in foil or using airtight glass jars, so their odor doesn’t spread through the freezer.²

How long frozen thyme keeps

Source	What it covers	Figure
Ohio State University Extension¹	Frozen herbs, best quality	Use within 3 to 6 months; may be safe after a year or longer
Usai et al., 2009⁴	Thyme frozen and held at -18°C, tested every 3 months	Smallest essential oil loss of the three methods over 9 months; no shelf-life figure
Colorado State University Extension⁵	Frozen vegetables in general, at 0°F or below	High quality for 12 to 18 months; no figure given for herbs
USDA freezing fact sheet⁸	Frozen food in general	Safe almost indefinitely; storage times are for quality only

“Use within six months” is a common rule for frozen thyme, and it matches the top of Ohio State’s range for herbs in general. None of these figures was measured on the flavor of frozen thyme.

What the research shows

Researchers in Sardinia split fresh thyme and rosemary into batches that were air-dried, frozen or freeze-dried, stored them for nine months, and analyzed the volatile oil every three months. The frozen herbs were packed in polyethylene bags and held in the dark at -18°C.⁴

For thyme, essential oil yield fell most in the air-dried samples, and the frozen samples showed the least reduction.⁴
The authors concluded that freezing was the best way to stabilize both herbs, and called the results preliminary.⁴

The report names the compounds that changed but gives no yield figures, and it did not use tasters. So it supports the claim that freezing holds thyme’s aroma oil better than drying; it does not tell you how long frozen thyme stays good or how it tastes next to fresh.

Freezing still changes the leaf. The water in the leaves expands as it freezes,² and herbs have textural changes after being frozen and thawed.¹

Food safety

Thyme in oil. Low-acid foods such as herbs, stored in oil, sit in an oxygen-free environment. Oregon State explains that such mixtures must be stored correctly to prevent botulism, caused by Clostridium botulinum, a bacterium found in soil, water and air.⁷ Its rule for homemade herbs in oil is to refrigerate and use within 4 days, or freeze for long-term storage.⁷⁹ A 2011 review concluded that freezing is the safest recommendation for home-prepared herbs in oil.⁹ Do not store herbs in oil at room temperature.²

ATK notes that oil cubes can be thawed and drizzled over food.³ That works for a flatbread or a finished dish if you thaw the cube in the refrigerator and use it within the 4-day limit;⁷ don’t leave thawed thyme oil sitting out.

After thawing. Freezing at 0°F inactivates bacteria, yeasts and molds, but once thawed they can become active again.⁸ Ohio State’s advice is to handle thawed herbs with ordinary food-safety care.¹ We found no source for how long thawed thyme keeps in the refrigerator. If you need to thaw it, the safe ways are in the refrigerator, in cold water, or in the microwave.⁸

Using frozen thyme

Add it frozen, in the same amount you would use fresh.²
Cook with it. Ohio State lists soups, stews, sauces and other cooked dishes as the best uses for frozen herbs.¹ LSU AgCenter groups thyme with the less delicate herbs that tolerate heat,¹⁰ so frozen sprigs can go in at the start of a braise or soup (editorial).
Oil cubes suit dishes that start with oil in the pan.³
Not as a garnish. Thawed herbs are limp and generally unattractive on a plate.²

See cooking with thyme and thyme uses.

Refrigerate, freeze or dry?

Refrigerator, for short-term use. America’s Test Kitchen stores fresh thyme in its original packaging or an open zipper-lock bag in the refrigerator.¹¹ See how to store thyme.
Freezer, for months. Holds more of the oil than drying in the Sardinian study.⁴
Drying. A real alternative for thyme. ATK lists thyme among the hardier herbs that dry well,¹² and in its fresh-versus-dried tasting, dried thyme fared reasonably well in long-cooked dishes.¹³ See fresh thyme vs. dried.

Not yet measured

A storage time for frozen thyme based on flavor; the one study found reports oil trends without figures.
How long thawed thyme, or fresh thyme, keeps in the refrigerator.
A safe storage time for frozen herb butter.
Whether ice cubes, oil or dry-pack freezing keeps thyme best.

Preserving Herbs: Freezing and Drying (HYG-5360), Ohio State University Extension. ohioline.osu.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹
Freezing Herbs, Penn State Extension. extension.psu.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³
Everyone Should Have Herb Ice Cubes in Their Freezer, America’s Test Kitchen. americastestkitchen.com · Publication ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶
Usai et al., Italian Journal of Food Science, 2009. iris.uniss.it · Peer-reviewed ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶
Preserve Smart: Freezing Herbs, Colorado State University Extension. apps.chhs.colostate.edu · Reference work ↩ ↩² ↩³ ↩⁴ ↩⁵
Preserving Herbs and Vegetables, NDSU Extension. ag.ndsu.edu · Reference work ↩ ↩²
Herbs and Vegetables in Oil (SP 50-701), Oregon State University Extension Service. extension.oregonstate.edu · Reference work ↩ ↩² ↩³ ↩⁴
Focus on Freezing, USDA fact sheet (copy hosted by the North Carolina Department of Agriculture). ncagr.gov · Regulator ↩ ↩² ↩³ ↩⁴ ↩⁵
Nummer et al., Food Protection Trends, 2011. foodprotection.org · Peer-reviewed ↩ ↩²
Flavorful Herbs, LSU AgCenter. lsuagcenter.com · Reference work ↩
Our Guide to Fresh Herbs, America’s Test Kitchen. americastestkitchen.com · Publication ↩
When You Should Actually Use Dried Herbs, America’s Test Kitchen. americastestkitchen.com · Publication ↩
Science: Substituting Dried Herbs for Fresh, America’s Test Kitchen. americastestkitchen.com · Publication ↩

Can You Freeze Thyme? Methods, Storage Time and What the Research Shows