Blog · Storage
How to Store Basil: Why the Fridge Turns It Black, and What to Do Instead

Basil hates the cold. Chilling can blacken its leaves and dull its smell,1 so the usual herb advice, wrap it and refrigerate it, is a compromise for basil. For a few days, keep it cool but not cold, with the stems in a glass of water like cut flowers. For months, freeze it in cubes of water or oil. And if you make pesto, there’s a 4-day fridge rule worth knowing.
At a glance
| How long you need it | Best option | Notes |
|---|---|---|
| A few days | Stems in water, loosely covered, at cool room temperature2 | Sources disagree on the fridge; see below |
| Up to a year | Frozen, in water or oil cubes or blanched leaves34 | Frozen herbs go limp when thawed, so use them in cooked dishes4 |
| Pesto or basil in oil | Refrigerate and use within 4 days, or freeze5 | A botulism precaution, not a quality tip |
| Long term, for cooking only | Dried | Much weaker than fresh6 |
Why basil hates the cold
Basil is prone to chilling injury, Rutgers Cooperative Extension tells growers, and the signs include blackened leaves, discolored stems and lost aroma. Rutgers puts the best storage temperature at 55°F with 90 to 95% relative humidity, and reports that basil stored between 50 and 68°F was in much better shape after 10 days.1
How fast the damage shows depends on both the temperature and how long the basil sits there, according to UC Davis’s Postharvest Research and Extension Center.7 A 2023 UC Davis dissertation adds two details that help at home:
- Some basils are touchier than others. Lemon and Genovese basil were more sensitive to chilling than purple, Thai and holy basil.8
- Cold dulls flavor, not just looks. Storing Genovese basil at the chilling temperature of 5°C (41°F) cut its volatile compounds enough to change how it smelled and tasted.8
Those are growers’ and researchers’ numbers for commercial handling. We didn’t find anyone who measured basil in a home fridge. UC Agriculture and Natural Resources says a home refrigerator typically runs at 40°F (4°C),9 which is colder than Rutgers’ range and a little colder than the 5°C in the dissertation.
Short term: counter or fridge?
The sources split:
| Source | Advice |
|---|---|
| The Kitchn (Emily Han)2 | Trim the stems, stand them in a glass of water like cut flowers, cover loosely with a plastic bag and leave on the counter. Says this can keep basil fresh and green for up to a week or two, and that refrigeration can turn the leaves black. |
| America’s Test Kitchen10 | Treats basil as a delicate herb: wrap in slightly damp paper towels, put in an open zipper-lock bag, and refrigerate. Delicate herbs should not touch liquid, which encourages rot. |
| Rutgers Cooperative Extension1 | For growers: 55°F is optimal; standing stems in water can reduce water loss. |
ATK’s method keeps delicate herbs moist, but it puts basil at fridge temperature, which the chilling research says is too cold.8 For basil you’ll use in a few days, a jar of water on a cool counter out of direct sun fits the chilling research best. If your kitchen is hot or you need it to last longer, the fridge is the trade-off, and you should expect some darkening. That’s our read of the sources above. We didn’t find anyone who’s tested the two head to head.
Washing. If you wash basil before storing it, dry it well. ATK recommends spinning herbs in a salad spinner lined with paper towels.10
Freezing basil
Freezing is how you keep basil for months. Quick-frozen herbs keep up to a year if they’re well packaged, Colorado State University Extension says, and they’re best in cooked dishes because they go limp when thawed.4 Oklahoma State University Extension adds: don’t thaw herbs before adding them to cooked dishes.3
Water cubes. Fill an ice cube tray halfway with water, add about 1 tablespoon of chopped leaves to each section and freeze. The next day, top off with water so the herbs are fully covered, and freeze again.4
Oil cubes. Oklahoma State mixes 1/3 to 1/2 cup of oil with 2 cups of chopped herbs, roughly 1 part oil to 4 to 6 parts herbs by volume. Herbs frozen in oil hold their color better than herbs frozen on their own, it notes.3 Keep these cubes frozen and drop them straight into the pan. Oregon State University Extension says homemade fresh herbs in oil must be used within 4 days or frozen,5 so a cube that’s thawed goes in the fridge and gets used within 4 days.
Blanched leaves. Oklahoma State suggests blanching the leaves of larger herbs like basil for 15 seconds to stop enzyme reactions, then plunging them into ice water. Pat them dry and freeze them flat in zipper-lock bags. Laid flat, herbs freeze and thaw quickly, and you can break off what you need. You’ll often read that blanching is what keeps basil bright green. Oklahoma State’s reason is stopping enzyme reactions, and its color note is about freezing in oil.3
Packaging. Double-wrap strong-smelling herbs in foil or keep them in freezer jars so the smell doesn’t spread.
More detail: can you freeze basil.
Pesto and basil in oil: a safety rule
Fresh basil in oil, pesto included, is a low-acid food in an oxygen-free environment, which is exactly where Clostridium botulinum can grow. Oregon State’s rule for homemade pesto: refrigerate it and use it within 4 days, or freeze it. You can freeze pesto in ice cube trays, then wrap it cube by cube. The same 4-day limit applies to dried herbs in oil.5
PROSEA records an Italian practice of keeping dried basil leaves in olive oil, which it says turn black but keep their flavor for several months.11 That’s a tradition, not a tested safe method. For anything homemade, follow the extension rule: refrigerate and use within 4 days, or freeze.5
Drying basil
Drying keeps basil for months, but it costs you most of what makes basil worth having. ATK puts basil among the herbs that are better fresh and much weaker once dried.6 If you dry it anyway, do it fast and cool:
- Mold risk. The National Center for Home Food Preservation (NCHFP) lists basil among the high-moisture herbs that mold if they don’t dry quickly.12
- Temperature. PROSEA says to dry basil leaves at no more than 35°C (95°F).11 NCHFP’s dehydrator range is 95 to 115°F,12 and Penn State’s is 95 to 110°F.13
- Microwave. Basil dries well in some microwaves, Penn State says,13 and Colorado State says to use the microwave’s low setting, checking every 15 seconds.4
- Air drying. In a 2004 lab study, basil air-dried at room temperature lost only small amounts of aroma compounds, while oven drying at 45°C and freeze-drying lost a lot.14 At home the catch is speed: slow air drying is when basil molds.12
- Done when the leaves crumble and the stems break when you bend them.
Most dried herbs keep well for up to a year, Penn State says.13 For the full method, see how to dry basil.
Using stored basil
However you store it, basil is a finishing herb. LSU AgCenter lists it among the delicate herbs that should go in a minute or two before the end of cooking.15 Frozen cubes can go straight into a sauce near the end.3
Not yet measured
- How long basil lasts in a home refrigerator compared with a jar on the counter, in a controlled test.
- How long frozen basil keeps its aroma, measured on basil rather than herbs in general.
- Whether blanching changes frozen basil’s color or flavor.
Related
- Basil
- Can you freeze basil?
- How to dry basil
- Dried basil vs fresh
- Cooking with basil
- Basil uses
- Basil vs Thai basil
- Genovese basil
- Too much basil
- How to store cilantro
- How to rehydrate herbs
Footnotes
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Fact Sheet FS1283, Rutgers Cooperative Extension. njaes.rutgers.edu · Reference work ↩ ↩2 ↩3
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The Best Way to Keep Basil Fresh, The Kitchn. thekitchn.com · Publication ↩ ↩2
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Freezing Herbs, Oklahoma State University Extension. extension.okstate.edu · Reference work ↩ ↩2 ↩3 ↩4 ↩5
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Herbs: Preserving and Using, Fact Sheet 9.335, Colorado State University Extension. ccfruitandnuts.ucanr.edu · Reference work ↩ ↩2 ↩3 ↩4 ↩5
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Herbs and vegetables in oil, SP 50-701, Oregon State University Extension Service. extension.oregonstate.edu · Reference work ↩ ↩2 ↩3 ↩4
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When You Should Actually Use Dried Herbs, America’s Test Kitchen. americastestkitchen.com · Publication ↩ ↩2
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How long does it take to show chilling injury on basil?, UC Davis Postharvest Research and Extension Center. postharvest.ucdavis.edu · Reference work ↩
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Rodeo, Basil Postharvest Chilling Sensitivity, PhD dissertation, UC Davis, 2023 (abstract). escholarship.org · Reference work ↩ ↩2 ↩3
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Garlic: Safe Methods to Store, Preserve, and Enjoy, ANR Publication 8568, UC Agriculture and Natural Resources. ccfruitandnuts.ucanr.edu · Reference work ↩
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Our Guide to Fresh Herbs, America’s Test Kitchen. americastestkitchen.com · Publication ↩ ↩2
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Ocimum basilicum (PROSEA), Plant Resources of South-East Asia. uses.plantnet-project.org · Reference work ↩ ↩2
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Herbs (Drying), National Center for Home Food Preservation. nchfp.uga.edu · Reference work ↩ ↩2 ↩3
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Let’s Preserve: Drying Herbs, Penn State Extension. extension.psu.edu · Reference work ↩ ↩2 ↩3
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Díaz-Maroto et al., Journal of the Science of Food and Agriculture, 2004 (abstract). agris.fao.org · Peer-reviewed ↩
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Flavorful Herbs, LSU AgCenter. lsuagcenter.com · Reference work ↩