How-to Guide
How to Preserve and Freeze Basil
The short answer
Freezing keeps basil closer to fresh than drying does, which strips much of its flavor. Two reliable methods: blanch the leaves for 15 seconds, plunge them into ice water, pat dry, freeze on a tray, then bag them; or blend the leaves into an oil paste (about 1/3 to 1/2 cup oil per 2 cups basil) and freeze in portions or an ice-cube tray.
One food-safety rule matters: only add oil to basil that you will freeze. Never store herbs in oil at room temperature, because that creates a botulism risk. Frozen basil darkens and goes limp when thawed, so it's best stirred into cooked dishes rather than used as a fresh garnish.
Why freeze instead of dry
Basil is one of the herbs that keeps its flavor far better frozen than dried. Penn State Extension notes some herbs hold their flavor better when frozen than dried, and specifically lists basil among them, and University of Minnesota Extension says freezing basil usually gives a product with a flavor more like fresh basil.
Drying works for woody herbs like rosemary and thyme, but tender basil tends to lose color and aroma when dried. If you want that summer basil taste in winter cooking, freezing is the method to reach for.
The blanch-and-freeze method
Blanching sets the color and stops the enzymes that degrade quality. Penn State recommends blanching basil leaves for 15 seconds to stop enzyme reactions, then immediately plunging them into ice water to stop the cooking. Drain and pat the leaves dry.
Freeze the leaves in a single layer on a tray first, then transfer them to freezer bags or containers once solid, which keeps them from clumping. Blanching also cleanses the surface and helps retain color and vitamins.
Oil, pesto, and the safety rule
Oil methods protect flavor and color well. Penn State suggests mixing about 1/3 to 1/2 cup of oil with 2 cups of chopped herbs and freezing it in trays or jars, or blending 1/3 cup oil with 2 cups fresh herbs into a smooth paste. Herbs frozen in oil hold their color better than those frozen dry, and this works especially well for basil. Pesto also freezes well for long-term storage.
The safety point is non-negotiable: oil should only be added to herbs if the mixture will be frozen. Do not store herbs in oil at room temperature, because low-oxygen oil at room temperature can allow the bacteria that cause botulism to grow. There are no home-canning recommendations for pesto, so freeze it instead.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- Penn State Extension - Freezing Herbs — States some herbs (including basil) keep their flavor better frozen than dried; recommends blanching larger herb leaves such as basil for 15 seconds to stop enzyme reactions then plunging in ice water; suggests mixing about 1/3 to 1/2 cup oil with 2 cups chopped herbs to freeze (or 1/3 cup oil with 2 cups herbs blended to a paste) and notes herbs frozen in oil keep color better; and warns that oil should only be added to herbs if it will be frozen and not stored in oil at room temperature.
- University of Minnesota Extension - Growing Basil in Home Gardens — States that freezing is a method of preserving basil that usually results in a product with a flavor more like fresh basil (compared with drying).
- National Center for Home Food Preservation (University of Georgia) - Freezing Pesto — States that pesto may be frozen for long-term storage and that there are no home-canning recommendations for pesto.